Well, this is interesting, just used my card against a paid stay, and received another identical email with the same offer 2 days later, which I just responded to.

So now we'll see if I get another gift card to use, or $1,500,000 in my savings from that poor, exiled Nigerian despot

EDIT* - yes, received another email with another $25 card that I just used, no problems. Great way to keep me staying at inexpensive BW's!