It is mine!!!

When I quit my job, various managers, proving that great minds think alike, gave me a grand total of $400 worth of gift certificates to a local independent bookstore. I stopped by today to pick up a copy of Lincoln's Melancholy for myself (gave it to my sister and her husband for Christmas and made the deadly mistake of reading the first 30 pages myself before I wrapped it) and ended up buying The Complete New Yorker, which I've been lusting for since it was first announced. I think it's the perfect use of a gift certificate: I'd never buy it for myself if I had to pay cash, and it's probably the largest number of quality words obtainable for $100. Now I just have to install the dang thing. Can I put it on both my computers?