For anyone who is interested, the replacement I found is Avangate (URL below). They will be handling the sales of my Made-for-FileMaker solutions through my web site from now on. They certainly made it easy for me to set it up. One thing I like is that they have a network of affiliates that you can use to sell your products (for a commission). Once you allow it, vendors all over the world will begin linking to your products.
If anyone has experiences (positive or negative) with this company, or a better alternative, I'd be interested to know.
I tried Avangate for the last six months. They haven't paid a dime on sales made through their service. They have been evasive and unresponsive to all my attempts to be paid and failed to honor my demand that they cancel my account when I replaced them with another company. Formal complaints have been filed with the appropriate consumer protection agencies. (PS Not one sale was made through their affiliate network.) Just wanted to pass the bad word.
I was finally able to reach Avangate's attorney (after filing a complaint with the San Francisco Bay Area Better Business Bureau). I was ultimately paid all moneys owed me my account was closed, as I requested.