Just want to point out that if you order straight from BattleCorps, Catalyst gets more of the actual profit. Catalyst profit converts to more products and depth to the universe.
While this is true, there is another aspect to it. If you (and some other) buy shadowrun books from your local bookstore, then they are more likely to order more shadowrun books, and with more shadowrun books on the selves, shadowrun will get more exposure, thus it might lure in more potential buyers. When you order books online, you usually know roughly what you want to buy, so you search for it, then you might get a few suggestions (hey, you like shadowrun, how about trying Eclipse phase?), but for the most part, you will be limited to things that already are within your slice of reality. It is a lot harder to randomly browse books online and find something new and unexpected than it is in a bookstore. When I had a good FLG in my area, I would sometimes go down there, check what they have and buy something on a whim, simply because it looked cool (had I not found that shiny Shadowrun 3rd edition book in my local gamestore, I would probably not be here now).
And heck, you don't actually have to buy shadowrun specifically to make it more likely that they order shadowrun books. If people are buying several different RPGs, then it is more likely that they will get a small stock of several different RPG books, and possibly order some other books while they are at it. Sure, it might only be 1-2 shadowrun books, but if those sell, they might order a few more, and suddenly you have a decent selection of shadowrun related material in your local gamestore.