The problem with this seems that the only people who will buy this are the people who spend more than $1k/mo on flights, so they'll end up having a really hard time making money. But I'd love to be proven wrong.
(The heck, I read their whole faq despite being on the other side of the ocean without any need to fly because I find the idea so intriguing..)
The people willing to pay 1k/month for this are probably not in the group of people looking for $80 specials.
Those specials are also inflexible and require either advance planning or a lucky weekend special. The target market for something like this is frequent fliers who need complete flexibility.