I just started yesterday. I'm at 9 with two already posting.
1. Marriott Transfer (10K to 2K). No real cost as these were pretty much orphaned points. I don't stay at Marriott (I'm always Hilton) and I didn't really have enough to do anything else with them. (POSTED)
2. Biscoff - $30 including shipping
3. DM Shopping - Made a $5 donation to PetsMart charities.
4. ShareBuiler - Opened an account. Hopefully the 2,500 miles show and count as a hit without having to trade.
5. Magazines for Miles - -500 DM for Details (POSTED)
6. DM Toolbar Searches (did 9 for 3 miles)
7. SkyMall - Bought a bottle opener that I will actually use.
8. Thanks Again - 500DM for Facebook Like
9. Points.com US-AA-US conversion. The 10US miles are out of my account. Just waiting on Points to convert them so I can convert them back.
I'll have the following in the next few weeks:
10. Hertz rental
11. SuperShuttle
12. DM Dining
Possibles in the future:
13. 1800Flowers
14. Audience Rewards
15. FTD
16. OfficeMax (waiting for the bugs to be worked out)
17. Teleflora
I have a work trip next week (see 10-12 above) and I'm staying at a Homewood Suites. Since their US miles "awarded" is below the minimum for this contest, I'm hoping to get a hotel stay later. With the extra HH points from their double promotion, I'll consider transferring points for a hit. I also have a trip to London next month where I'm staying with a friend, and I may consider staying a night in a Hilton there (although it would be mighty pricey).
Realistically, I'll get to 16 hits. If work travel picks up, and I think it will, with the car rental and hotel hits, 24 might be attainable.
Right now I'm at 0.003469 per mile if everything listed above in 1-9 counts and hits my account.