Not Getting It

So for Fathers' Day I bought my Dad a bottle of port from M&S and had them deliver it as he's 100 miles away from me. That all worked splendidly. And then a few days later I got this email. It began:

Well, I purchase from the M&S web site once in a blue moon, and it always seems to work just fine when I do, so my self interest in helping them "improve our website and service to you" is pretty limited. Certainly not enough to want to spend ten minutes of my time over a survey.

But perhaps there's some incentive? Like entry in a prize draw, that sort of thing?

Oh yes, so there is: their thanks.

I don't think M&S get it (or my answers to their survey).