I received this email from NW. Have any of you tried this? what do you get out of it?

As a WorldPerks member, we’re extending an exclusive invitation for you to earn WorldPerks miles and share your opinions with
e-Rewards®!

You can earn WorldPerks miles by simply responding to e-Rewards e-mail and participating in surveys that have been pre-screened to match your interests. You’ll help shape future products and services from major companies — and get rewarded for your time.

Enrolling in e-Rewards is quick, your privacy is guaranteed and there’s no cost to participate. Plus, enroll in e-Rewards today and you’ll get a valuable Welcome Gift as our way of saying thank you.