I must admit I hadn't thought of it in that light, its so obvious and, once pointed out, makes sense to me.
I won't say I never gift aid, but the way I do it I guess sits somewhere in the middle.
For example I don't gift aid where it actually costs me more e.g. National Trust properties and similar (I'm a NT member anyway but wouldn't pay the gift aid price if I weren't)
I definitley gift aid if there's something in it for me - e.g. some museums will give a years free admission at no extra cost if you sign the forms.
Charities I don't, simply because I'm usually just putting coins in boxes/buckets on shop counters etc. and can't be bothered with the little envelopes.
As for the rest - depends on the day, but in future I'll perhaps be thinking of soapbox' comments and the implications.
But then again, having read other's comments, maybe not