Social networking site Twitter has revised its terms and conditions in a move that will allow the micro-blogging service to run ads as a way of making money.

Earlier in February, Biz Stone, Twitter's founder, had indicated that the site could go for ads to generate revenue.

However, Biz Stone said that they had no intention to allow the ads immediately.

But, he added, "We leave the door open for advertising. We'd like to keep our options open, as we've said before."

It should be noted here that most probably many companies will show reluctance in juxtaposing their brands with unpredictable comments from users. User-generated contents may be offensive too.

Twitter, which allows users to post messages of 140 characters or fewer, has 45 million users worldwide.