Thank for the explanations!
I have been completing surveys on E-Rewards for the past year, just waiting to get to $100 to transfer to HHonors, but now I have a better destination for $25.00 worth of them! Funny thing is I had a big lag in invitations over the last few weeks, then I read about this promo. I'm glad for the lag, otherwise the credit would have been long gone.
Signed up for E-Miles a couple of nights ago and am patiently clicking through the links, up to 325 points. Pretty tedious but worth it!