everything!!!
this is the kind of investment that anyone should stay away from and never invest, if i correctly understands the person should get referrals for have profit as MLM and Matrix site, I hope I am wrong because few people get some referrals and never saw anyone say which reached the last level but the site owner who most of the time is a scammer always has profits from these schemes. And you still ask what can go wrong? It's obvious that everything will go wrong.
this is only in theory because the practice shows that the person only spends a lot of money pragging advertisements on other sites to get referral and in the end does not gain active referral and the site closes causing you to waste time and money