One day a week, Xur and the Cryptarch meet up in a bar somewhere in the tower and share their stories...
Xur: "Dude, this guy gave me 23 motes of light for a golden engram. I told him to take it to you to reveal its godly content lol. What did you give him?"
Cryptarch: "An exotic helmet, of course...but I had to make sure it wasn't for his class lmao!"
Xur: "That's my boy! Now, they'll have to come back to me for more. At this rate, I'll be able to retire in a few months! Anyway, what do you have lined up for the rest of the week?"
Cryptarch: "You know...just the usual. Turning blue and purple engrams into green boots!