BeTheBest it really depends on your target market and being persistent, I agree for most small businesses there are far faster ways to make some coin like email.
My favorite twitter quote "Send 10,000 tweets then tell me twitter doesn't work", funny because it's true, you can't expect to tweet a few hundred times and be rolling in connections and clients.
Some of the above strategies focus on the I follow you if you follow me, I don't really buy into that, you just end up with a heap of bots and non engaged followers. Just check my account for an example http://www.twitter.com/buzzdan
over 500 followers, I would rather have 100 engaged people.
Put out good content regularly and you will get followers, it takes a lot of time. I use http://timely.is
each morning to post articles I know small businesses will be interested in (it schedules posts throughout the day). This takes less than 10 minutes.
At the end of the day the posts that get the most clicks, I repost on Google+ and Facebook using Hootsuite.