I have around 2,500 followers atm, mostly indiedev types and indiegame fans. Still doesn't do much though - perhaps I'm not merciless enough in promoting my stuff there!
I also have a dev blog / official website for the Captain Disaster games and books. Occasionally I get some traffic and very occasionally a sale from there. Otherwise some traffic comes from reviews on the bigger sites (JustAdventure, GameBoomers) and forums (again GameBoomers, and AdventureGameStudio). I've tried to get reviews on places like indiegame.com, PC Gamer and RPS, but no joy there.
Twitter is a big part of my strategy in terms of finding reviewers and streamers to contact. Well, insomuch as I actually have a "strategy"!