I know Frontier and the ULCCs aren't everyones' cup of tea (A319s, low seat pitch, charge-for-everything), but if you live in or near a city where they fly non-stop to LAS (or LAS itself to other places),
they have a 3X miles promo going now for bookings thru Wednesday 9/13 and flights thru 12/14 where the BONUS MILES ALSO COUNT TOWARD ELITE STATUS
No registration required, but of course you have to have an Early Returns account (free).
By my calculations an ATL-LAS RT bought under the promo would have 3,480 flown miles, or 10,440 RDMs or EQMs. They currently have a SAVE90 promo going (also through 9/13), so I've seen ATL-LAS RTs as low as $58 RT if you're really date-flexible (and not too bad on other dates except Sun.). If you got the $58 it'd work out to $0.0055 (slightly over half a cent) per EQM.
I see no mention of limits on using the deal as long as the bookings are done on time and the trip is by 12/14, so it looks like you could get the two trips (could be done as instant-turn MRs if necessary), enough RDMs for an off-peak RT anywhere they fly in the 48US (or a peak OW), AND enough for elite status, all for $116.
The elite status is noteworthy because Frontier is unique among ULCCs in still giving modest perks that make the flying experience more bearable, such as a free (fullsize) carry-on, pre-boarding, ability to select most seats free at time of booking and upgrade to stretch seats in the 24-hour check-in window. They're basically giving you a standard legacy-airline experience (almost) if you're an elite. Which is much more than you get with Spirit and other ULCCs.
YMMV and it only applies to their flights to/from LAS. OTOH, I recall some of the hub-attack mileage promos the legacies USED to do when there was more competition, such as a 3X-er CO did back in 1993 for people in ATL. It seems the ones with some excitement potential like this have gotten fewer and farther between over the years.