What would be the point of having fake followers. They provide no real interaction. I personally use TweetUp. Depending on the campaign I run I may follow users in my niche based on keywords. If there is a popular user in my niche I will follow their followers. Social media is all about egos and if a user follows you back then they are stroking theirs, till later when you allow the software to unfollow all of them. So in this process you gain laser niche targeted followers, that are real and care about what you tweet about. You also don't look like an idiot with 1,000 followers with profiles from India or another 3rd world country.
There are better ways to invest your money for the long term rather than buying 1,000 fake followers for $5 that will most likely drop. (Don't worry people over-deliver, L hoe freaking L)