aion expansion game

okay gamestop is selling the gamestop expansion digital for 20.00 this week online and i know its exactly like if you where buying a store copy. my main concern is with buying this does it also include the main aion game and the expansion or is it just the expansion idk this is prolly a stupid question. Althought idk what to expect when i see how wow does there expansions so it doesnt hurt to ask please can someone help me before i decide to buy?