The internet is similar to mail order but faster with a lot of tricky details (in the same way that mail and print have tons of tricky details). People don't ch

The internet is similar to mail order but faster with a lot of tricky details (in the same way that mail and print have tons of tricky details). People don't change all that much. 'Free' gets you a lot of tire-kickers automatically, whereas a guarantee pre-qualifies the customers to the people who can afford to float you some cash. If they're a tire kicker, at least they're not a totally broke / budgetless tire kicker. There are other free sweeteners that you can offer that aren't a free trial.