US miles as low as 1.1cpm (DM Multiplier promo)
 

Aug 13 through Sept 12 you get 50% bonus miles on DMM purchases if you actually complete the trip. The lowest you can normally get is 1.6cpm, which gets to 1.1cpm with the bonus miles.

http://www.usairways.com/en-US/divid...ultiplier.html

I'm quite familiar with DMM (Dividend Miles Multiplier). How do you get to 1.1 cpm? I can't get a calculation to get me there.

For the 1.6cpm you need to be booking itins close but below 12,499. Then you pay $399 for 24999 RDM on DMM, which translates to 1.6cpm.

Does the 12,499 include Preferred bonus miles?

No, you need an itin with base mileage close to 12,499. I usually use TATLs from the west coast for that.

You can do better than that. Including the preferred bonus, get as close as you can to 25,000 without going over. As a gold, I use SFO-TLV. Buy the triple for $599, and you get just under 50,000 miles. That is 1.2 cpm, and with the promo it's 0.8 cpm. Too bad you have to actually fly it to get the bonus!

That's still a nice strategy even without the 50% bonus for actually flying. ^

Yeah, wow -- that's a game changer. Seems like messing around with promos and stuff is a bit of a waste of time.

Do the miles post instantly upon purchase of the ticket?

Yes they do.

Yeah, I did this one twice and they posted immediately. I am not sure how many times you can do this and cancel without raising a red flag.

Any reason why it should raise a red flag? I haven't seen any rules prohibiting this (but I haven't looked thoroughly).

I did a search and found this post, would definitely have some reservations about doing this:
http://www.flyertalk.com/forum/17823409-post8.html

So I am about to book an October flight to FCO and I am looking at the multiplier deal. With out the 50% it is 1.6cpm (ho hum). But with the 50% bonus it is 1.05, which is a good enough deal for me to do it.

The T&C states that purchase needs to happen in Aug 12-Sept 12 and I assume the flight can be later, although that is not explicitly stated.

Should I do this?

So let me get this straight. One could book a Flexible fare and pay for the DMM, cancel the flight and keep the DMM?

Yep.