The usefulness of Twitter now stands to be further comprimised by new initiatives to entice power users to tweet for cash.

Anyone who uses Twitter can tell you what a royal pain it is to sift through spammy tweets in search of the interesting stuff. And now the company behind a controversial pay per post blogging program wants in on your Twitter feed, too.

While Izea believes sponsored Twitter postings will be “self-policed” and not run roughshod over the popular service, Twitter users know all too well how hard it is for people to resist the lure of incessant self-promotion and marketing. When directly linked with tangible financial gain, how long will it be before Twitter is useless due to the volume of spam?

This isn’t the first time Izea, formerly called Pay Per Post, has stirred up controversy in the blogosphere. From the AdWeek piece:

Izea is not without its critics, which assert that the company’s paid bloggers often do a poor job of disclosure. Julia Allison, an Internet celebrity of sorts, was heavily criticized for posting about Sea World without disclosing that her coverage was part of an Izea program. She subsequently updated her post to reflect that connection. The Federal Trade Commission recently set new guidelines for bloggers who endorse products for payment.

Even Izea’s CEO Ted Murphy admits the idea has the potential for abuse, saying:

“The question is going to be how do you meter it to make sure it doesn’t get crazy.”

If the recent Spymaster craze is any indication, it’s only a matter of time before Twitter is overrun with #spon hashtags