Note that many websites have their own advertising, unrelated to adware.
From Coupons, Inc., "From time to time Coupons, Inc. may collect information before or after you print a coupon, or with no associated coupon. In some cases, we will collect personal information on our own behalf to fulfill your requests for offers and promotions, provide you with ongoing promotional opportunities and to send you advertising and promotions on behalf of our clients and advertisers. In such cases you will always be provided with notice that we intend to collect personal information and you will have an opportunity to opt-out of future messages or use of your personal information."
Coupon toolbar that gets integrated into Internet Explorer.