Join Date: Dec 2002
Location: Danville, CA, USA;
Programs: UA 1MM, WN CP, Marriott LT Plat, Hilton Gold, IC Plat
Posts: 17,987
As noted above, when using the magazine method "confirmation of extension was instantaneous."
I have used the iTunes method with US Airways, and I think the miles posted within a week or maybe less. Very fast compared with other merchants.