Exclusive: Want More Followers? Twitter May Help You Buy Some.

Want more people reading your tweets? Twitter may offer you a hand–for a price.

People familiar with the company’s plans say it has been discussing yet another revenue generator: Think of it as a “Promoted Tweeter” product, which highlights specific user accounts, designed to bump up follower counts.

My sources weren’t sure about the business model behind the product, which may be because Twitter itself doesn’t know yet. Some obvious possibilities: Twitter could charge users based on the number of followers they acquired, or simply based on the exposure their Twitter accounts received.

Twitter wouldn’t acknowledge plans for the product at all. Here’s spokesman Sean Garrett, via email: “We will eventually have full suites of both promoted and commercial products. All the components of these two buckets of product have yet to be determined. Some are currently being tested publicly now. Some will be tested soon. Some are just ideas that we are broaching externally for feedback.”

If Twitter does move forward with its plans, it would represent a change in philosophy for the company, which has generally frowned on third-party companies that promise to build up follower counts–even though Twitter itself promotes specific accounts for free, via a modified version of its “suggested user list.” But TweetUp, a prominent and well-funded new start-up, has its own follower-building offering, so perhaps that has caught Twitter’s eye.

My sources say Twitter has discussed using the yet-to-be-named product both on its own Web site as well as third party clients. That would track with other Twitter revenue projects, like “Promoted Tweets,” its play on Google’s (GOOG) AdWords, and “Promoted Trends,” which it just recently launched on its own site but plans on moving to third-party apps as well.

The biggest question: What, exactly, is the value of a Twitter follower?

Twitter’s original “suggested user list” effectively granted a select group of users with follower counts of a million or more. But it’s clear that the majority of those followers, who signed up when they opened accounts, tend not to pay much attention. A smaller, but much more engaged, audience of Twitter readers can be much more valuable. But figuring out how to price that will be a work in progress.