BlogDay
BlogDay was created with the belief that bloggers should have one day dedicated to getting to know other bloggers from other countries and areas of interest. The designated date is August 31, because when written 3108, it resembles the word "Blog". On that day, bloggers recommend five new blogs to their visitors, so that readers discover new, previously unknown blogs.

Blog search engines
Several blog search engines are used to search blog contents, such as Bloglines, BlogScope, and Technorati. Technorati, which is among the most popular blog search engines, provides current information on both popular searches and tags used to categorize blog postings.
The research community is working on going beyond simple keyword search, by inventing new ways to navigate through huge amounts of information present in the blogosphere, as demonstrated by projects like BlogScope.

Blogging communities and directories
Several online communities exist that connect people to blogs and bloggers to other bloggers, including BlogCatalog and MyBlogLog. Interest-specific blogging platforms are also available. For instance, Blogster has a sizable community of political bloggers among its members.

Blogging and advertising
It is common for blogs to feature advertisements either to financially benefit the blogger or to promote the blogger's favorite causes. The popularity of blogs has also given rise to "fake blogs" in which a company will create a fictional blog as a marketing tool to promote a product.

Popularity:

Researchers have analyzed the dynamics of how blogs become popular. There are essentially two measures of this: popularity through citations, as well as popularity through affiliation (i.e. blogroll). The basic conclusion from studies of the structure of blogs is that while it takes time for a blog to become popular through blogrolls, permalinks can boost popularity more quickly, and are perhaps more indicative of popularity and authority than blogrolls, since they denote that people are actually reading the blog's content and deem it valuable or noteworthy in specific cases.

The blogdex project was launched by researchers in the MIT Media Lab to crawl the Web and gather data from thousands of blogs in order to investigate their social properties. It gathered this information for over 4 years, and autonomously tracked the most contagious information spreading in the blog community, ranking it by recency and popularity. It can therefore be considered the first instantiation of a memetracker. The project is no longer active, but a similar function is now served by tailrank.com.

Blogs are given rankings by Technorati based on the number of incoming links and Alexa Internet based on the Web hits of Alexa Toolbar users. In August 2006, Technorati found that the most linked-to blog on the internet was that of Chinese actress Xu Jinglei. Chinese media Xinhua reported that this blog received more than 50 million page views, claiming it to be the most popular blog in the world. Technorati rated Boing Boing to be the most-read group-written blog.