I think Pokemon, along with magic and yugioh, are the three trading card games that won't go under if TPCi, WOTC, or Konami did something really dumb to drive off sales.
WoWTCG is sort of joining the club, but not fully in the club. If WoWTCG made some minor mistakes, then it wouldn't go under, but if made a major big one, the game is done. Pokemon TCG on the otherhand, if TPCi did a major mistake to drive away sales, it would just be unpopular for a while, and then the popularity will rise again.
At least that's what I think.
Games like Kaijudo and CF Vanguard can't afford to make mistakes, considering they are brand new and all.
I also find that the newer TCG's, that just started tend to not have a release pattern, and sets are just released whenever. WoWTCG does have a release pattern in that it releases 3 sets a year, but they don't release them in the same time each year.
We have Magic that releases a core set every july, the first set of the block every october, second set in february, and third set in may. Duel decks are released every march and september, FTVs in august, and a supplemental product in June.
Yugioh, same thing. Boosters in January, May, August, and November. Structure decks in February and October, and Starter decks in the middle of the year.
Pokemon too. February, May, August, and November are their booster releases, and they seem to release a bunch of box sets in which they have some sort of a release pattern, but I am unsure if it really is a pattern.
Now, the reason why Pokemon, yugioh, and Magic releases 4 sets every year is because of comparing sales figures to previous years sales figures. Well at least that is WOTC's explaination why they decided to release coldsnap and eventide, and change the biannual core set release to an annual one. It is kind of hard to compare sales when you release 3 of something one year, and 4 of something another year, so now, it means that these 3 TCG's are past the being established stage, and are on the making as much money as possible stage.
In video games, on the other hand, when companies are establishing themselves, they tend to make quality games, and are in it with the fanbase, but when they start going mainstream, and or in the point where they are making money, and any mistake they do won't destroy the company, unless it is a series of mistakes of course, then they start to do the cash grab, and make the same game over and over, and target those who don't realize that they are paying for the same game. This couldn't be said for TCG's though, well I do kind of feel like I am paying for the same experience when I buy more cards though.