Just to toss this out to anyone looking for another alternative, we're using Plimus for our latest title, and had been using DigiBuy for seven years prior. Both are pretty good, and Plimus is popular among indie developers (I believe they even allow your customers to pay using PayPal).

I think you'll always get fraud orders, as Ello says, but if you're selling in any volume, then the time required to manually process orders would be more productively spent elsewhere (my opinion only :).