Alphawolf, that is an interesting idea to payout per site review instead of hourly.. $2/site might be reasonable. It would certainly encourage them to review more sites and they'd get paid for work completed not time (they could be really slow).
Crunching some test numbers, lets do some math!

Let's say:
- Reviewer spends ~ 2 minutes average per site review (sometime more sometime less)
- So reviewer can get through 30 Sites/Hour
- You get around 60 submissions per Day
- This will take about 2 hours per day to do all reviews
(Am I way off here? .... lol)
The Various Payout Models For This Amount of Work:
60 Sites @ $20 Per Hour:
$20/Hour x 2 Hours = $40/Day (Reviewer Makes $20/Hour)
60 Sites @ $2 Per Site:
60 Sites/Day x $2/Site = $120/Day (Reviewer Makes $60/Hour!)
60 Sites @ $1 Per Site:
60 Sites/Day x $1/Site = $60/Day (Reviewer Makes $30/Hour) <- Best Deal For Everyone?