I mean if the decision were phrased 'Would you rather pay a babysitter, take your SO out for an excellent meal, followed by a night of drunken shenanigans, and finish up making passionate love in a wonderful hot tub suite at a local hotel or would you rather buy an iPad?' than the only people buying an iPad would be the very lonely or those with a direct business interest.
It's just hard to keep that kind of perspective sometimes.
In regards to the one day hot tub experience, I think people can logically amortize the cost of the iPad/iPhone over the months and years that they'll use it. And, I believe if a device brings a little bit of boredom breaking into your daily routine, why deprive yourself (you're not hurting others with your purchase decision)?
The difference pointed out by the study is that the memory of the steak is likely to make you happier in the long run than owning the hot tub even though the steak is long gone and the hot tub is still there. After all, the hot tub will eventually become a chore (repairs, cleaning, upgrades, etc...) but the memory of that steak never really dies if it was extraordinary. It's counterintuitive, but it makes sense to me.
This study is why I've started trying to focus on experiences, rather than things, when buying gifts. So far it's worked out rather well for me.
That is, if you buy it because you can find some use in your life. If you just buy it cause it is new then you won't get so much happyness out of it.