The only way that a user could take advantage of multiple accounts is that they would be able to get more faucet requests and potentially rain from chatting.
As in the formula DogecoinMachine posted, as well as the faucets investors also pay for referral income. This is the most common reason people cheat with multi-accounts. Self-referring has a far higher potential gain than faucets.
I didn't even consider the self-referring. That would definitely be a good way to abuse multiple accounts.