Jenna Wortham, on Bits Blog:
"Tweet," for posting a message, has become a common word, but that's not all. "There's already a microsyntax on Twitter," he said. A word like "follow" (to subscribe to someone's Twitter feed), and the symbols @ (denoting an online name) and # (a "hashtag," denoting a searchable topic) have specific meanings on Twitter that have begun to migrate across the entire Web and beyond. "Even people outside of the site understand what that means," he said.
The same goes for products that have entered the online vernacular: to Google or Facebook a person; to get fireballed; your Klout. This is the tipping point for an online product. Funny thing is this wasn't always the case:
"In the past, Xerox ran a very expensive campaign in places like Editor and Publisher that said don't use xerox as a verb," she said. "What people know from marketing experience now and what people now understand as a practical matter is that it is very good when people use your name as verb."