Media commentators have long fawned over social networking site Twitter and the speed it can shape opinion, but all have asked the question, how do they make any money?

A proper advertising system may now be in the offing - The Wall Street Journal's tech blog has just reported on plans at Twitter HQ to incorporate advertising into the micro-blogging service's search facility, so that when you search the tweetosphere for tweets on, say, "New York", you'll see an ad for things to do in New York. When you search for tweets on "laptops" you'll see an ad for laptops.

It will work like Google's basic search-linked ads system, though ad copy will have to be 140 characters long, so they take the form of a tweet.

Users are fearful that Twitter will become saturated with advertising and "corporate accounts," it could drive away many users.

They should be much more obvious than the current text ads that appear on the web-based Twitter interface, and it's thought the firm will sell the new ad spots much more proactively, the existing ones generally just promoting Twitter-related services. It's thought these new ads would also show when searches are done off the Twitter network via third party clients like Tweetdeck. People who primarily connect with Twitter using such apps currently completely avoid all Twitter advertising.

According to the WSJ the new ad system should go live this side of the summer.

Additional Reporting by CMU Network