We always ask customers to pay for the first month and then we can discuss payment for a longer period.

There is a number of reasons, firstly we can get a taste of how much of a burden this user will be on support (if they're opening 10 tickets a day we'll give them less discount for bulk payment than someone who never bothers us).

Secondly it usually gives us time to detect if the user is fraudulent and slipped through our filters and it means if we have to refund it's not such a big deal.

Thirdly the customer may not like our service so we prefer them to test for the month before they commit for a longer term. This also means you don't have to work out silly amounts because they want a refund for their 2 months and 2 days remaining service. That said not that many people really like to prepay, at least that's what we find.