Originally Posted by
tomcat007
To prevent miles from expiring (not a lot) is it advisable to buy miles directly from united or get this card?
None.
The easiest way is to buy a 99 cent song/app from iTunes from the MP mall:
https://www.mileageplusshopping.com/...rch_box&mids=3
or do a free survey for miles:
https://www.opinionmilesclub.com/