If they were trying to run these login campaigns to get extra money from alternate characters, it'd be terribly ineffective. Each extra character is only $1.00, and the rewards aren't particularly enticing. I have 4 mules which predate the login campaigns and which I for some reason haven't cancelled yet. Most of the time I find myself with 4600 points at the end of the campaign and going "ok so now what do I do with them?"

If they wanted to entice people to get extra characters for more points, they'd make the rewards more consistent (not changing every month) and better. They'd probably also let you mail the pop items they keep giving away, or the XP ring.

See now I play an actual Freemium game, Simpsons Tapped Out, and their model actually makes the things you buy with the real world money worth it. You can barely get anywhere without ponying up cash for donuts.