TwitPub has set up shop as a Twitter marketplace — that is, a place where you can, say, sell horoscopes or stock tips on Twitter and make money from Twitter users who subscribe to your offering. TwitPub calls these subscriptions “premium tweets.”

All you need to get started is a private Twitter account or an account that has its updates protected. From there, you sign up for a TwitPub account, and the service automates the process of subscribing through its website. You get to choose the subscription rate for your new service.

TwitPub says its platform could be used for a variety of “useful” information, including jokes, horoscopes, or breaking news. But I’m having a hard time seeing the value here. It all sounds an awful lot like those premium text messaging services you see advertised on TV (you know, “Get daily horoscopes sent to your phone free!”) or that you can subscribe to through services like Frengo.

And I’m not sure TwitPub’s business model will hold water. There are already Twitter users out there doing for free what TwitPub aims to charge for — here’s somebody doing horoscope tweets, and another doing a Joke of the Day. Besides, the culture of Twitter is very much a free flow of ideas.

So far about 30 people have registered some type of offering through TwitPub. One is offering trading tips for 99 cents a month; another is charging $1 monthly for Feng Shui advice. Most of the other services I checked were also priced right around a dollar. Under TwitPub’s agreement with its publishers, it receives a 20 percent cut of that monthly fee.