Many people who start using Twitter just want to get heaps of followers as quickly as possible. Maybe that's because they want to feel like celebrities, or intend to spam people. These are bad motivations for obvious reasons.
However I think most people who do use the social networking site sincerely still feel a pressing need to try and get lots of followers, and soon. It's only natural. And of course you want as many people as possible to read what you have to say in your tweets.
One of the main ways that Twitter newbies try to get those numbers up quickly is by following tweeps primarily in the hope that a certain percentage will follow them back. But in the end I think the best policy is to try and curb that need for quantity and keep looking for quality.
If you don't do this you'll end up with heaps of irrelevant or just plain spammy tweets in your timeline. So you'll have to spend more time wading through them to find the nuggets that you can learn from, retweet and reply to.
If on the other hand you make a point of following really good people in your niche, then that river of tweets will be consistently golden. You'll find interacting with the people you follow a lot easier and more rewarding.
Not only will this get their attention -- making them more likely to mention and retweet you, thereby lifting your profile -- you'll also accumulate far more tweets up there on the site, meaning you're more likely to get found by people looking for others to follow.
Sure, a certain proportion of these followers will be low quality themselves, but there will be some goodies. And they will have chosen to follow you because they liked what you had to tweet -- not just because you followed them. That's a better way to kick things off, surely.