Yes it works well for me & I Tweet other Hubbers articles that are relevant to my niche. It's primarily a weight loss account though anything related to health and wellness gets traffic.
If you are looking to build up a Twitter account in a particular niche the software "Tweetadder" is great. Don't spam it though otherwise you'll lose your Twitter account. I just use it 3 -4 times a week and no problems so far.
To get an idea of the amount of traffic Twitter can get you go onto Fiverr and put down a Clickbank affiliate product to someone who has a tens of thousands of followers. If you do it consistently you'll get sales and look at the huge spike in your CB account.
The key to Twitter traffic is to have a niche account and build up 1,000s of followers. Takes time but well worth it! Cheers, Barry ;)
Ps; Oooppps forget to say I got a guy from Fiverr to set my Twitter account so up to date niche related articles go out on autopilot. That way if you don't get chance to Tweet manually all the time then your followers don't lose interest.