Note that many websites have their own advertising, unrelated to adware.
Zango-WallsofJericho is a vector for Zango's Search Assistant and displays popup advertisements based on websites visited.
From EULA :
The Licensed Software may collect, and transmit to Zango (referred to in the EULA as "we" or "Zango"), information about the websites you visit ("Usage Data"), as described in more detail below.
While the Licensed Software is installed on your computer, Zango may collect information about you and the websites you visit.
The frequency of these advertisements will vary depending on your use of the Internet.
The advertisements that the Licensed Software presents are provided in a separate browser window and are not endorsed by or affiliated with the websites that trigger their appearance.