The main atraction of AlertPay over PayPal for many online marketers is that AlertPay allows you to operate a multi-tier affiliate program and pay affiliates via AlertPay. PayPal won't , it will restrict (close!) your account for breaching its draconian Acceptable Use Policy.
Bottom Line: it's almost impossible to trade for more than five minutes online without breaching PayPal's AUP. It's so broad in scope, and so sloppily-drafted, that everyone's in breach, one way or another.