Probably the more appropriate question is - how it's different than http://minted.com? I know TinyPrints is not crowd-sourced, but Minted is.
Please note, I'm not trying to demean your service or existence by any means, but just trying to learn how you're distinguishing and plan to compete with this super growing startups?
Edit: Nevermind, answered it myself. Chirply does all paper goods, whereas moonpig only does cards, flowers, gifts, and bottles.