Your ad will become live as soon as you purchase an advertising spot inside the Smart Installer Pack software.
If you download SIP you will see the system in progress (it's the banner at the bottom of the software on all download pages).
Everyone who uses SIP will then see your ads on live immediately after you bought one.
All you have to do is click this link: get your ad inside SIP
then follow the instructions on the resulting page. You will also be able to see how many ad spots are still available.