I can actually be hired to throw sarcastic comments at your product and or idea for as little as just 99 cents per message.

In addition to offering 'hired guns' users could get suggestions automatically mined from other users with highly rated replies (similar to A.L.I.C.E) . The UI could be mass effect style with an array of choices:

I.e

T: what are you up to

derivative conversation detected! (read in a protoss voice)

Y:

   nothing u? (swipe left)

   busy go away (swipe right)

   returning video tapes (swipe up)

   robbing a bank (swipe down)