I have purchased music from the iTunes Store with a gift card, so I answered Yes here. I was pleasantly surprised to find Paul Hardcastle's eponymous album (featuring "19", "King Tut" and "Rainforest") on iTunes, with a slew of bonus tracks that kept me from having to record both my LP and my 12" single of "19", both of which have seen better days.
In the interest of full disclosure, the vast majority of my music is either ripped from CD or recorded from my vinyl/cassette collection, a sizable portion of which is obscure to the point that even pirate sites/torrents probably wouldn't have it. Example: There is a track on the vinyl and cassette versions of The B-52's Whammy! album called "Don't Worry", a remake of a Yoko Ono song. When Warner Bros. wanted to reissue it on CD, Ono wouldn't license the rights to the song again, so another track was put in its place on the CD. I had to record that from cassette. The rest of the album I ripped from a CD I got in a used music store. (Many of my CD replacements are from used stores-- I already paid full price for the album the first time around.)
My wife has purchased more from iTunes and/or Amazon than I have. We have Home Sharing activated, so I have a couple of tracks from her collection. She has way more from mine, though. She was initially leery of buying online via iTunes, as she got rather badly "burnt" when the first incarnation of Walmart Music closed up shop, but she likes it now; she's one of those "music consumers" that buys only the top hit singles, listens to it a few times, then moves on to the next hit single.
Like maflynn, I like not having to mess about with physical media. I would have loved to have had an iPod in my high school days. Bringing along several cassettes ("What were those?" I can hear some of you younger ones ask) and a player in a duffel bag on school trips was nowhere near as convenient-- and battery life flat-out sucked.