Of course, they are great, for the member.
However, webmaster promoting the sponsor's site/s may not agree, especially once they've realize that they will not be paid the same for the sale, at least from those (sponsors) that pay out more than the price of the membership.

Example: Our flat rate subscriptions with exits are $29.95USD.
We pay webmasters $35.00 ($40.00 for 6th and on).
At the very least, we lose $5.00 on the initial sale ($10 for 6th, & on, SU).

Eliminating re-occurring charges has removed most of the potential of extra earnings for us, which will force us to drop payouts to something more realistic, like $20.00 for all SU, or maybe even lower!