Note that many websites have their own advertising, unrelated to adware.
AproposMedia is the advert-showing part of the 'PeopleOnPage' program, an Internet Explorer sidebar which claims to show a list of other users of the current site.
From their Website:
POP! World is being provided to you free of charge in exchange for your agreement to download and view advertising served via ContextPlus (a proprietary browser-based advertising delivery system). ContextPlus will deliver advertising on your computer screen on behalf of POP advertising clients. These advertising clients may be competitors of the publishers whose Web pages users may be viewing or may have viewed recently. By viewing advertisements served via ContextPlus ("ContextPlus Ads"), POP is able to subsidize the cost of providing you POP! World
Go to the Control Panel's Add/Remove Programs feature. Select and remove 'AM Server' and 'POP'.