There are a few posts running here and on the Geek regarding how we increase the player pool.
My overwhelming recommendation would be to launch an on-line play platform (cf Memoir 44, Small World, Ticket to Ride, Pandemic, etc., etc.). OCTGN does a cracking job of allowing one to actually play the game, but is a little difficult to set up initially. Nowadays, for 'a little difficult to set up initially' read 'dead in the mainstream'.
There is another suggestion, however, which may help to extend the player base. Advertise to specific groups beyond CCG or LCG players. I am not really a CCG or LCG player, but I understand that such games are short (30 min?) and somewhat strongly affected by the card draw. Players who are looking for 30 min battles may get fed up with Mage Wars.
For me, Mage Wars is much more akin to Warhammer, Hordes, and other various miniatures games. Players spend hours in advance designing armies (spellbooks), choosing upgardes (enchants, equips) which are all available during play (not a card draw), involve tactical positioning (we have a map!), and the occasional special effects (attack spells?). These games take from an hour to maybe 3 hours typically. The players who enjoy these games might be a great target audience for Mage Wars.
Now the elephant in the room here is the MINIATURES themselves. Many people play Warhammer (et al) for the painting and spectacle. I personally hate painting but love gaming, so Mage Wars is a dream for me. I reckon there will be a decent market for players who feel like this, or who no longer have the time to paint hundreds of minis. Those guys are probably a bit older and more affluent now. Again, a GOOD THING for Mage Wars.
In addition to the tired Warhammer (et al) players, there is a market of Wargamers who I KNOW would love Mage Wars if they could get beyond the fantasy trappings. Even with the dripping theme, I believe that if grognards were to give the game a go, we would generate many converts. The complexity of MW is NOTHING compared to the stuff that grognards put up with. There might be an argument to say this market is too small, but recent releases such as I-pad Battle of the Bulge are driving interest in this level of game.
In summary...Mage Wars is a cracking game. OCTGN does a valiant job of allowing on-line play, but an official platform would be even better. Targetted approaches to miniatures and board wargamers might be worthwhile.