People have registered via valid links on United's website, have been confirmed as registered (me among them) and are now spending thousands of dollars (not $40 and 4 miles) using United-branded credit cards to get the stated bonus miles. In so doing, we are foregoing whatever benefits we might have received by using other credit cards. That's tangible damage that United is doing to us if the Airline later claims their confirmed offer isn't applicable. Moreover, changing the terms and conditions ex post facto isn't applicable, Jeff Baby. If we need to reside in Latin America (or on the Moon!) to get the bonus miles, then United better say so before accepting our registrations and then letting us spend our money in reliance upon their fulfillment of the bargain.

RNE, phraphrasing Wayne Campbell, "The bonus miles will be mine. Oh, yes, they will be mine!"