Originally Posted by Boraxo
Not sure how the "mileage deposit" could possibly help you with programs like Starwood and Amtrak which require actual stays (or an SPG Amex) or train trips to extend the life of your account. I'm sure there are others that have similar requirements.
Not true in either case! You can transfer Diners Club points (at the very least) into Starwood:
https://www.citibank.com/dinersus/js...egory=e350b05d
as well as into Amtrak:
https://www.citibank.com/dinersus/js...egory=9837b40b
And you can exchange Hilton HHonors points into Amtrak:
http://hhonors.hilton.com/en/hhonors/rewards/rail.jhtml
And I doubt those are the only ways, but that's enough to prove that there are multiple ways to refresh those accounts "from partners", depending on what else you have.
But therein's the problem: Refreshing many accounts
does depend on what else you have. Which would make a service like this very complicated to set up and manage. The most able to do it would probably be points.com (since they're already set up to do transfers between a number of programs), but given their track record at providing value (not!), you can guess how much they'd charge for every automatic "ping" of an account!