Thats because trampling over with big numbers is part and parcel of being in green, and because generally green has plenty of redundant effects and redundant win conditions, so the support cards are way more important
I like them in mono-colored decks as welltwo lands for one card is never out of style, especially when I am playing a deck that really wants a bunch of lands
Earning these counters is fairly easy, all you have to do it tap it to deal one damage to a creature you don't control
If the matching allied fetches get announced, watch out, because these will all end up at a grand each
Your commander itself starts the game face up outside your deck, in a special area called the command zone
During a Magic: The Gathering Zendikar Rising preview at SDCC@Home today, Wizards of the Coast revealed a brand new booster pack type that will debut with the expansion, called the Set Booster