Collectable-type games have emerged as one of the most profitable genres in tabletop gaming. Probably THE most profitable. Unfortunately for game publishers, it seems to be getting harder and harder to succeed with this model every year. Now, it was always hard, but lately nothing seems to have legs. Remember the World of Warcraft TCG? I'm told it was huge. It's probably still a good seller, but huge? No. I thought the new Pokemon Collectible Minis game would be a big hit with the younger players. It wasn't (discounted at my local games store.) It may be that Pokemon has finally worn out its welcome, but I really think there's something else at work.
1) Established brands (Magic, Clix, ect.) still dominate. There's simply no room for any other brand to get significant traction.
2) Slow economy. Other forms of entertainment, particularly electronic, provide more entertainment for less money.
3) Scorched Earth. Greedy rarity schemes and failure to successfully promote secondary markets have created an industry with a reputation for ripping its customers off, one $4 pack at a time. This mindset, more than anything (IMHO) is preventing quality collectible games from reaching the fan-gamer. These games are now being dismissed by gamers out of hand.
Whether or not a collectible game can overcome this stigma is hard to say. My guess is that it won't, because I don't know of any publisher whose willing to sacrifice short term sales to create a stronger product overall. I've never worked for one who would.
Rares sell packs, they say. To much crap in the pack kills games, I say.