What is Twitter?

Watch this video below on a simple explanation about Twitter:

How Can Using Twitter Help Promote your Wiki?

You can use it as an RSS feed king of things, about your wiki. Other Twitter users can see it, get interested to see what is happening on your wiki, and eventually go to your wiki and possibly become members.

What are people doing on Twitter?

People are reading about Wetpaint Central and going to it right now, from Bedding7's Twitter account.
Here is an photo from Bedding7's Twitter account: