O.P. is only Offering $15 for the Review and if O.P. will hire an escrow from the Link that you share, he needs to pay $28.59 just to make sure that the Transfer will be safe and Secured.
The escrow minimum Fee of the link that you shared is 0.001 in BTC.
it would be best if O.P. will send half of the amount of the reward to His chosen candidate while doing the review.
Money is needed in marketing. Because of lack of money, many project failed. I hope OP can understand what I am talking about. He wants people to review a site for him, he needs more reviews and needs to do things in a way that people will know their efforts to increase traffic into their website.