[freeflight]

But many people are very reluctant about signing up with their debit card details with too many companies, at least I know I am.

Unlike CC you don't get a new number/have half a dozen of different ones of them. So it's a quite a bit more of a hassle should the payment service provider ever have a breach/leak.

Many people didn't like to sign up with PayPal to begin with but, due to its dominance with eBay it was a bitter pill most people just swallowed to do their eBay buying and selling.