I found it a little strange today as I bought something from the store where the cashier asked if I had an e-mail address to send my receipt to. I have had this before when stores simply ran out of receipt paper as the business was literally closing down, but that didn’t seem to be the case here. I did give out my e-mail though with a little reservation.
Maybe it’s just me, but I am still in the mindset that if a brick and mortar store asks you for an e-mail that it will somehow be used to send you marketing information. Almost no different than subscribing to a newsletter where the trade-off is that the business now has a huge list of potential customers to sell to over and over again. Of course that may not be the case at all here.
Generally speaking personal information is big business too and so I am usually a little paranoid when companies ask for these kinds of details when they shouldn’t have to. I guess that is why too for things like e-mail you should often have your main address and one designated for contest entries and such. Unless this is a new thing that businesses are adopting to save paper.