I guess I've been a real slacker: No social media, no surveys, no wine clubs. I had gone some 19 years without a pure MR until a $138 BNA-RDU RT with a huge bonus mile deal of some sort proved too tough to resist a couple of years ago.
OTOH, the old system of flying-for-miles just isn't being rewarded like before. With MQDs/PQDs, DL and UA want 10 cents per EQM and count only purchases on their ticket stock (a real stealth gotcha), whereas FTers want to pay only around 4 cents, less if possible. I'm unlikely to go beyond silver, if that, on spending patterms and already have that as a MM'er. So DL just went from a program that could incentivize trips that wouldn't have happened at all to "What's the incentive to fly?", which is a spectacular drop in effectiveness for a loyalty program.
And Spirit's alternative is 50% miles and aggressive expiration with mediocre award levels UNLESS you're a cardholder (which many of their customers would not qualify for), so the only real game there is with the credit card (and, for those who are so inclined, MS). Again, no real incentive to fly, at least on paid tickets.
Having some 21 years now of online bookings and the fly-for-miles model (starting with command lines and EAASY SABRE on CompuServe, if you can believe), you could say I liked the old system and have been slow to change, but it's hard to deny that the current system and alignment of rewards can lead to credit-card churnin', spendin'-manufacturin', fuel-dumpin' super-cynics.