It's up to you, obviously, but I found the pushiness extremely off-putting. You need to decide whether the core user activity is writing documents or inviting their friends. If it's writing documents, get rid of the invite clutter. If it's inviting friends, well, good luck, but the app is gone from my profile.

Actually, if you don't mind, want to post your invitation code? (Or email me, [email protected].) Looks useful :)