Originally Posted by amanuensis

I don't know what you have in mind, but my "trick" is to click on the e-mailed survey invitation links a second time about I finish doing the surveys that I initially got offered and sometimes I get a fresh set of surveys. YMMV.

A variant "trick" is to first click on the survey invitation link using my iPad and do the surveys that I am offered and then click again on the invitation link using a different devices, such as my laptop. Frequently, this results in me getting a fresh set of surveys. But I am not sure whether this would have happened anyway had I used the same device for both clicks, since as my first paragraph notes, you sometimes get more surveys after a second click even when the same device is being used both times.

Periodically, the e-Rewards logged-in home page will have survey offers waiting for you -- surveys that never got an e-mail invitation sent. So it always pays to check it after completing a batch of surveys that came via an e-mail link.