It's kind of interesting how things build on off of others, and yet diverge wildly. Wargaming minis spawned D&D. And while the spell mechanics of MtG were inspired by Cosmic Encounter, the combat is familiar to D&D players, and caught on like wildfire among the RPG community.

And MtG in turn has inspired a number of games, beyond simple CCG clones. MtG booster pack drafting inspired 7 Wonders and a number of similar games. Deck customization aspects inspired Dominion and countless other Deck Builder games. The whole CCG aftermarket trading / tournament scene inspired a game called Millenium Blades.