You don't have to tweet but twitter is very useful for finding out up-to-the-minute info on a lot of things e.g. important things like news stories that the usual media choose not to cover or lesser things such as "is there a problem with the company from whom i've ordered goods?" or "what's the latest on that new film release?", and with some of those you'll tend to get information that is much more recent than a convention internet search provides.