Once you break through the 2K followers mark, you can only follow 10% more tweeple than are following you. So a different method is needed to increase your follower count quickly.

Here's how I get upwards of 400 followers a day (and niched too!):

Step 1: Every morning 7am and evening 11:30pm I go to my favorite internet marketer's profile, and follow all the tweeple in the first few pages.
Step 2: There is no step 2

It really is that simple. Of course I'm a bit more selective than that, I only follow these kinds of people:

* People that have an avatar

* People that have a pretty balanced number of followed-followers

* People that have something related to SEO, internet marketing, niche marketing, or anything else relevant in their blurb

* People that have tweeted in the last 12 hours

My follow-back ratio is around 80-90%. Here's why this works: most of these people *are* interested in my tweets since I'm in their niche, and most of these people are avid followers, and most of these are either online or have been recently, so the chance they're going to be online again soon is good.

Each page of followers takes me around 3-5 minutes depending on how congested twitter is, so I can follow around 400 new people in 1hr. Once I get above 10K followers I'll be able to follow 1K at a time, so I'll probably outsource this activity.

I've also decided that I'm going to clean up my non-followers each week. Twitter Karma http://dossy.org/twitter/karma/ will show you your non-followers ordered by most recent tweets first. I unfollow everyone that has tweeted in the last day, because they were online and didn't bother to follow me, so they aren't likely to change their mind later. Twitter Karma also orders your followers by most recent tweets first. I'll unfollow anyone who hasn't tweeted for a month or more, reasoning that they're dead profiles and shouldn't take up space in my following list.

It sounds like a brutal system, and yes, it is!