I think that rent referrals is old and bad idea. Site can set attractive rules and lose money with every click or set good rules for site and than users are unhappy :-D Better is referral market like in adbtc where you can buy/sell your referrals and site have some fees from transactions. And everyone can be happy.
Its also a bit stupid i have been rented and renter payed 15k satoshis for me i already earned 45k satoshis for him and i will earn for 5 another days so he is good 30k satoshis plus another 5 days.I got just 5k as a sallary :/