I was also having a bit of a dry spell and too many of the "no-points" profile questions, but then I went back and clicked on an old "You Have a Survey" e-mail and got into one that qualified me for a REALLY lucrative study- don't want to give away details that they might want kept confidential, so I'll just say that it's detailed and over a long period, but nothing too onerous on a day-to-day basis.

This, though, points out one of the maddening aspects of e-Rewards.

Open up the splash screen: no new surveys.
Click on a link in an e-mail just received: this opportunity has expired.
Click on an e-mail received last week- you get directed to a lucrative survey for which you qualify.

I'm sure it makes sense to someone.