There are 21 different cards featuring the 3 Legendary Dogs: Entei, Raikou and Suicune
High-demand SP cards (particularly Luffy and Shanks variants) have sold for thousands of dollars
If you're playing Hearthstone and know that the new meta is dominated by gurgling Murlocs, you'd normally have no option but to buy a dozen random packs and hope you draw what you need, putting a quite a lot of money into ActiBlizz's pocket along the way (and even then you're not guaranteed that you'll get the cards you want, potentially prompting further purchases)
This indicates that, much like the physical Pokemon TCG, there will be at least six new sets each year
(You cant be the target of spells or abilities.) So great is his certainty that mere facts cannot shake it
There have been apps and websites in the past where you could and still can get cards but this mobile app is the next evolution, if you will