I've "earned" some, I've zurned some...who cares. I do nightfalls, raids, and PoE, and if Zur sells something I don't have, I get it. Chances are I will see it down the line, but at least I can get an exotic shard out of it. You don't earn anything btw, a random number determines your reward. If that makes you feel accomplished though, then by all means take it. You little earner, you!