It's a hair splitter but I don't think that's what they meant. They're specifically saying "purchasing experiences" which is where I think the distinction is.
I mean, it's hard to argue because in a lot of ways the question comes down to 'what constitutes buying an experience". If I buy a gadget I am buying an experience in using that gadget. So in that way purchasing items is also purchasing experiences which invalidates the article all together.
I think the social aspect mentioned would be key in differentiating the difference between the purchase of an object and an experience such as eating out, reading and commenting on HN, etc. As you say, it is a hair splitter and I'm probably stretching the theory behind the study and the conclusions way farther than can be justified.
I mean, it's hard to argue because in a lot of ways the question comes down to 'what constitutes buying an experience". If I buy a gadget I am buying an experience in using that gadget. So in that way purchasing items is also purchasing experiences which invalidates the article all together.