In these days, the widespread of the internet gives anyone the opportunity to share their thoughts and opinions to a worldwide audience. One of the most popular and common ways in the World Wide Web to do this is the blog which is an accessible venue to for people to express a variety of ideas.(Hui & Gregory. 2010)

The Blog word is derived from the word ‘weblog’ which means a web based log in which log means a journal. Blogs, or weblogs, have become a very noted type of social media. Authors, or bloggers, write articles and post it into the blog which then it become known as posts. These posts through the blog generate feedback from the comments of the readers. (Hui & Gregory. 2010)

Chin and Chignell (2006) define blog as a special type of a dynamic website which consists of periodic reverse chronologically ordered posts mostly on the same webpage. These posts vary in format from containing a list of hyperlinks to articles’ summaries allowing the reader to comment and rate. They also consider blogs as a mixture between persons and articles because, commonly, blogs are written and closely associated by a single author.

A typical blog articles may consist of text, images, videos and hyperlinks to other blogs or websites combined. These articles could be post or comments on posts. Blogs also can be divided into two types:

• Community blogs which are authored by multiple authors and they are a good resources for discussion about events and products.

• Personal blogs which are authored by one person, also known as individual blogs and considered as personal journal or diary. (Agarwal, N. 2008)

Blogs may contain categories and tags to help readers navigate and search more conveniently.

In September 2008 the famous blogs search engine Technorati has indexed 133 blogs since 2002. These blogs have attracted more than 77.7 million unique visitors in the US only. (Wang et al. 2009)

This show the huge impact blogs made to expressing ideas, sharing knowledge, reviewing products, influencing the market. through the internet.

The traditional web design model is in some ways similar to a book. The main page (homepage) has references to the primary pages and those pages acts like a homepage for the references they contain. Although the contents of these pages can be updated but it still considered as static website because the whole page must be edited every time a small change must be amended. The traditional web design is good for a site that is not going to be updated frequently.

Blog isn't intended to be navigated or used as a traditional web site. Blogs, usually consists of main page where every article posted on it in a reverse chronologically way and they are dynamic because of the easiness of posting any type of article in a fast and convenient way and because they are updated frequently.

Blogs can be broken into categories where each new post is assigned to a category, in order for the readers to sort only the information they want to view. (Williams. 2003)

Gardner and Birley (2010) claim that each blog, no matter what it is its contents must have these characteristics:

• Frequent Updates
• Posts
• Permalinks
• Chronological Order
• Comments
• Archives
• Categories

According to the dynamic nature of the blog posts and the structure of blogs it was hard to bookmark a blog post. To solve this problem permalinks which means permanent links that point directly to a post in a blog has been invented. Permalinks are effective solution that turned blogs from an ease-of-publishing website into a conversational array of overlapping communities. (Coates, T. 2003)

Technically, these permalinks are pointers stored in the database that point to main body of an article that is stored in the database also. They are called permanent, despite that every URL considered permanent, because if the article body changes or moved from the main page of the blog this pointer will still point to its location in the database.

As Agarwal and Liu (2008:1) state: “Individuals experience a sense of community, a feeling of belonging, a bonding that members matter to one another and their niche needs will be met through online interactions.”

In order to understand the how social networks and social activities behave on the internet we must understand the concept behind them which is virtual communities.

Chin and Chignell (2006) consider virtual community important because people tend to gain the benefits of social relations with other like minded people. They also define virtual communities as accumulated social discussions that emerged from the internet when people carry these discussions publicly with human passion and for a certain period of time to create networks of personal relationships in the internet, from this raised a new common point that members of a community experience which is “Sense of Community” (SOC) which they define as the feeling that members have of belonging, a feeling that members matter to one another and to the group, and a shared faith the members’ needs will be met through their commitment to be together .

Blogs are linked to each other through a social hypertext structure just like the World Wide Web, explicitly by links from one blog to another and/or by comments made by one blog author on posts by another blog author or comments made by readers, which all can be considered as links. (Chin & Chignell. 2006)

Hui and Gregory (2010) describe the blogosphere as the aggregation of blogs in the internet which consists of huge number of topics that cross-section one another.

Blogosphere is considered as one of the fastest growing, social media networks because the virtual communities in the blogosphere are not constrained by distance or time zones. (Agarwal, N. 2008) A Recent Technorati numbers show that blogosphere grows in a rate of one hundred percent every six months and it has grown over 60 times during past three years with approximately 2 new blog posts every second. (Agarwal & Liu. 2008)

Blogs have affected social interactions between people and communities by allowing people to discuss with other people on the other side of the world bout everything from regional matters to international issues. These social interactions are termed as social networks. Blogs can be considered as a type of social networks that contain interactions between different people. (Agarwal & Liu. 2008)

A research by Stavrositu and Sundar (2008) showed that blogs can empower users, by giving them the feeling that they can contribute to improve their situation, through sense of community.

Agarwal and Liu (2008) list Social networks services as follows:

• Blogosphere (e.g. Blogger)
• Social Friendship Networks (e.g. Facebook)
• Media Sharing (Pictures e.g. Flickr, Videos e.g. YouTube)
• Collaborative Annotation Environment (e.g. delicious)
• Wikis (e.g. Wikipedia)

They also describe the difference between blogosphere and a social friendship network is that the members of the blogosphere, the bloggers, don’t have a direct connection or explicit connection between them as the members of the social friendship networks. Although, there are similarities between blogosphere and social friendship networks such as collaboration, experience exchange and the sense of community.

Figure 2 shows the relation between blogosphere and social friendship networks and in what fields do they interact.

Blog authors usually described as columnists or interpreter. These terms may describe the some of the authors’ writing and observing habits but blog writers like to be known as hit reports with breaking new stories or documenting special experiences.

While blog post discuss significant issues with the public and build a reputation for the author these posts are used as archive and reference tools also. This behavior, using posts as sources for references when writing other articles, emerged because most of the authors, bloggers, work or involved in an activity related to their blog. (Carter, S. 2005)

A recent study by Efimova (2009) involved that a blog can provide a convenient and flexible personal management system as it serves as a simple way to create personally meaningful content and allows the author to start writing in small pieces that can be easily fitted between other activities, putting information into context and also putting irrelevant information for current goal but might be used later. The study also showed that structure of blog allow the author to organize and maintain information in a personalized way using chronological archive, categories, tagging or connecting topics through links. Another advantage, is when this information in blog and it is interesting for others, their feedbacks can enrich the author’s thinking about the topic and support the process of developing ideas overtime.

Chin and Chignell (2006) state that influence in any community is bidirectional, which means that members of a group will be empowered to have influence in the group while at the same time the group also has influence over them. Therefore, mutual links between blogs, reciprocal links, are considered as a structure for influence.

Figure 3 shows an example as blogger B has influence on Blogger A and his community because blogger B is connected to A, by reciprocal links, and A is part of a community which he can influence.

This shows that that blogs with more reciprocal links are most possible to influence. Also, blogs are considered an excellent source of information for commercial purposes, for example, predicting consumers purchase decisions and habits through blogs’ posts. (Chin & Chignell. 2006)

Moon et al (2010) consider blog as an influential blog if it triggers a reader reaction for a specific post either by leaving a comment, which may agree or disagree with the author or by recommending the post for others. If a blog succeeds to make its readers react by expressing their opinions through comments it’s considered as an influential blog.

Agarwal and Liu (2008) show that major studies by Ed Keller and Jon Berry in 2003 demonstrated the following:

• 83% of prefer people consulting family, friends or an expert over traditional advertising before trying a restaurant.
• 71% of people prefer to do the same before buying a prescription drug or visiting a place
• 61% of people prefer to do the same before even watching a movie

This shows that people are influenced by other people in almost every aspect of life, especially while consuming. This style of marketing is called “word of mouth”, where people are influenced by other people opinions more than traditional advertising.

Other studies show that people talk and listen before they buy, in which experts can influence their decisions. These experts are considered as Influentials.

A blogger is considered influential if he writes post that affects the opinions and decisions of other members. As they build up respect and reputation in the community over time, other members tends to listen to these inffuentials before making a decision. Since they can influence buying decisions they are potential market movers.

Blogs as a highly interactive medium host several discussions on various issues including new products, services, marketing and comparative studies, these discussions acts like “word of mouth”. Approximately 64% of advertising companies have acknowledged this face and are changing their adverting strategies and moving toward blog advertising.

Influential bloggers, beside of marketing, can change political opinions, elections and government policies or even change the whole government by moving masses of people and because they know a lot of people and soak up a large amount of information people consider influentials as reliable knowledgeable sources of advice and insight.

In another aspect, companies started to use these influentials in help and troubleshooting by creating blogs for these purposes in their websites, where people can discuss issues related to a service or product. Using these blogs and influentials, companies can improve their products and services by focusing on influentials suggestions and customers’ discussions.

The main source of bloggers’ influence is their posts. The influence could be measured by these posts through different measures like in-links and out-links which are reciprocal links, comments and post length. This could give us an influential historical info of who influenced whom. While members of social friendship networks don’t have such a medium like blogs through which they can assert their influence. (Agarwal & Liu. 2008)

To start giving an advantage to their members to influence, social friendship networks started to allow its members to create page and groups for certain cause with discussions and comments which I consider as blogs, but in a different names, inside these networks.

This paper explained the main concepts of virtual communities, what is a blog, what is the blogosphere and its relation with other social networks which led to the influence it makes over its members.

This paper also identifies the influence of blogs and its importance through describing how blogs can be an excellent advertising medium or even the first spark of a political typhoon. According to the above blogosphere is considered the most influential type of social networking models and most informational too.

Further research on blogs influence can lead to new era of predicting and directing human reactions and opinions toward specific things. Also further researches on blog post comments may lead to creation of a simple peer-reviewed system for blog posts containing scientific information.

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