Rocketmiles thru the Alaska Mileage Plan can be very generous with some more expensive venues offering up to 10,000 bonus Alaska Airline miles per night. As always your mileage may vary, and always check their price against what you can get from other sources. but for an example a 5 night stay at the Four Seasons in Vancouver, Canada, can cost you $1,844 but net you 38,000 bonus miles. That works out to 21.6 miles per $$ spent. If I charge up 5 nights with the AMEX PLAT direct, you only get 5 points per $$ spent which is still not a bad deal, but not Alaska Miles. 5 night in Newport, Oregon at a nice oceanfront hotel can run you as little as $816 and you get 8,000 bonus miles. That one works out to 10.8 miles per $$ spent. Those are pretty outstanding stays for bonus points earned. Not every stay is that generous and if you have a hotel elite status it may not be recognized if you book thru Rocketmiles, so be aware of that. I usually only look at using Rocketmiles in locations where my hotel elite status is not represented.
So far, it has been the most generous and quickest way to earn elusive Alaska Miles. Transferring Marriott points in 60,000 point bundles to Alaska runs at a rate of 2.4 to 1, not a great deal but close to the only transfer partner out there. 60,000 becomes 25,000 Alaska Miles.
There is a miles bonus boost feature in some reservations with rocketmiles but then you really are just paying more for additional miles. Do the math first.