If your are conducting research for a press article, product comparision one additional info for you:

IMHO Amex Membership rewards was the first programme with non-expiring points. If you are not elite member of a frequent traveller programme the most airlines (like Lufthansa) have an expiry date for bonus miles.

Only Membership rewards allows you to stack up the MR points as long as you want. And then transferring the points at the time you would like to use it.

Donīt know when they have introduced that "non-expiry policy" but this is the unique selling proposition /advantage for your research/article/press release/product description or whatever you research for.



Hope this helps.