Ask HN: Unique virtual product delivery solutions?

Does anyone out here have a preferred method for delivering unique virtual products (i.e. software licenses or pin numbers) ? I'm trying to recommend something for my father, who needs to deliver PIN numbers through a store front. The best solutions I've found are http://pomidorcart.com/ - about $450, or adding some bit of code to zen-cart to trigger a pin lookup on a table of pins and send the next unused one - just my time. I imagine that there are some people one HN who sell software (with licenses) so I'd like to ask what your solutions are (since it's essentially the same thing).