For example,
i send coins to escrow
escrow confirms this
you use your own coins and generate the profit
you send coins + profit to escrow
escrow releases my initial deposit to you and what you sent to him to me.
correct me if i'm wrong
then it is better to make a giveaway page
and wow what a bitcointalk where any person not have even 0.0001 to prove me right
People are not stupid.
I give you 0.0001, you pay me back as promised.
I give you 0.001, you pay me back as promised.
I give you 0.01, you pay me back as promised.
I give you 1
BTC and whoosh! you are gone.