Words with friends--inviting people to play?

I just received an invitation to play WWF from someone I don’t talk to any more. It could be his way of reaching out to reconnect, but I am suspicious that perhaps he merely receives some in-game benefit for getting more people to sign up. Can anyone shed some light? About possible benefits for signing people up, that is, not on his motivations…

There is no benefit at all to inviting people to play. It isn’t farmville or a game where you have to recruit players.

There’s a chance the person clicked on your name by accident. It isn’t hard to do. Or perhaps they just wanted to play the game with someone they knew.

I play WWF with random people all the time as well as friends I know in real life.