Most people are good at what they're good at, so it makes no sense for them to learn something they have little interest or skill in. The typical request from a non-tech guy is not in implementing a hard engineering problem like database management or search query structure, but in putting together what is typically a glorified e-commerce site or social site (digg etc).
Subsidies like these are inefficient for businesses because they don't discriminate between customers who are new to the business and regular patrons. It doesn't really increase demand so much as pull it forward a la "Cash for Clunkers" meaning you are subsidizing customers who would have bought anyways.
Gilt and its clones don't sell regular merchandise, but almost always out of season, overstock, and seconds merchandise that the firm would have to dispose of regardless. Businesses that use Groupon deep discount their normal stuff.
Why do you fear an employee would leave you after you invested in training him? Unless you are particularly abrasive, most employees would look favorably at an employer who helps them advance in their job than one who doesn't invest anything at all.