One, we need Twitter to actually consider the request.
Why? Just add #Bitcoin to the end of your tweets.
Probably the most effective way. In fact, we could have the Bitcoin Twitter hour where we all just pause for a moment and flood our timelines with stuff
I believe the most effective way to market Bitcoin via Twitter is for Bitcoiners to up their tweet count and include #Bitcoin to all those additional Bitcoin related tweets.
In the past, I've been involved with trending campaigns--started by other tweeps--that all failed to get a bleep on the TT radar. We would have had better luck if we used #whymybitchisahoandyourdogaint directed towards a certain demographics--at two in the morning.
Twitter is a powerful tool when used correctly. If not, it's a major waste of time or, worse yet, a campaign may backfire. Tread lightly!