I saw this game being advertised down in the dealer's room at Otakon 2 weeks back. I thought the art was really interesting but at the same time I'm not a really big card player fan so I just by passed the booth. I mostly play table top minuature games like Warmachine/Hordes and Warhammer 40k. As much as I love these kinds of games I find them hard to play with the amount of traveling I do. Being in the Army, it is hard to invest the money into these kinds of games and be limited on where you can play. (Not many comic book/gaming shops around the bases I have been stationed at) I must say though, Alteil has been a blast. It definatally has a lot more strategy involved than I would of expected and it's a load of fun. With as much moving around I do, and my desire to play these kinds of games, it is very convinent to just boot up my lap top and start a game whenever I want. I am really sorry I didn't try out the program or meet you all while at the con. I've introduced the game to a lot of my guy gamer friends at home to try out with high hopes!
Other places you may try to advertise would be comic book shops. Many comic book shops distribute trading card games and I think advertising a free online game along side with the ones you pay money for, maybe an idea. A very good friend of mine owns a comic book shop in our community so if you guys had any sort of advertising stuffs, I know he wouldn't mind displaying them.
Best of luck with what you decide on though