More than 700k sessions of Scrabulous are played on any given day by some 3.2 million Facebook users who have added this popular game to their profiles.

And Google AdSense is helping Scrabulous developers, Jayant Agarwalla and Rajat Agarwalla, monetize their creation.

The brother duo is making around $20k a month from AdSense ads that are displayed above and below the Scrabble board on Facebook.

In fact, this Scrabulous page on Facebook may be quite popular among advertisers because the audience on that page will almost always stay for an extended duration and they are therefore very likely to notice advertisements.