The well-regarded social media guide Mashable reports that Twitter has come up with an intriguing business idea – and one that could benefit businesses if they play it right.

The promoted tweet is an interesting concept which goes where no advertising system has gone before. Promoted tweets will appear (at first, anyway) in search results: imagine, for example, the benefit of being able to attach your name to any search for the name of your town, or a special offer to any search for your brand.

But it’s not just a matter of buying your space on the Twitter stream. Adverts will be rewarded for the level of engagement they provoke. Just as a standard tweet will be quickly forgotten if it isn’t retweeted or replied to, a non-compelling advert will sink, unnoticed.

Clearly, this is Twitter’s way of trying to ensure that adverts give something back to the user, potentially minimizing the predicted outcry from those who are used to tweeting cost-free.

Entrepreneurial businesses are already setting up auto-replies to any tweet containing a phrase they perceive to display an interest in their product, but the method is very hit-and-miss and runs the risk of irritating a user. This is a smart move by Twitter to try and reap some benefits from the opportunities that these chancers have already identified.