Contributed By: Charles Clarke [MVP SMS]
No it's not true. The time the advert arrives at the client depends on a number of factors such as the frequency with which the clients are checking the CAPs for adverts, when the advert was scheduled to be available, when the source files are being moved out to DP's (will impact on the successful running of the program), and a wee bit extra time that it takes the client to process the advert.

Adverts can arrive and run within minutes if you want them to! Check out the product documentation for more details:

http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/sms/proddocs/smsadm/smsad00.asp