Twitter is a popular microblogging tool that can be accessed via the web, instant messaging services, or SMS. Despite having some problems with uptime during the service's first few years, Twitter has remained one of the most used microblogging and conversational tools.
Part of what has contributed to Twitter's success is the flexibility of the content and the means of accessing it. Some users exclusively read tweets through the website, while others use a variety of desktop or smartphone applications, and still others rely only on SMS messaging to keep up with their Twitter stream.
The site was first embraced by social media advocates, and has since expanded from banal play-by-plays of daily activities to asynchronous and synchronous conversations between close friends and strangers alike on topics ranging far and wide. Much like blogs and MySpace profiles of the past, celebrities and politicians (or their staff) have created Twitter accounts to connect with and disseminate information to their fans and constituents. A less savory crop of "experts" have surfaced as Twitter's popularity has risen, many of whom claim to provide tips on increasing search engine optimization through the service.