(Text from Google Adwords)
AdWords ads are displayed along with search results when someone searches Google using one of your keywords. Ads appear under 'Sponsored links' in the side column of a search page, and may also appear in additional positions above the free search results. That way, you'll be advertising to an audience that's already interested in your business.
You can also choose to display your ads on Display Network sites in the growing Google Network. And, you can choose the exact Display Network placements where you'd like your ad to appear, or you can let contextual targeting match your keywords to content. You can choose from a variety of ad formats, including text, image, and video ads, and easily track your ad performance using the reports available in your account.
(Graphic and text from Microsoft)
"Start your search advertising campaign on Bing™, using Microsoft adCenter, and expand your reach to 82 million monthly users. It’s simple, easy and affordable.
(Graphic from HowStuffWorks.com)
Each banner ad graphic size would have associated html code to be inserted into search ads for organized insertion into their dynamic display program, or manually entered into cooperative web sites for static display. The graphic files typically remain stored on your website.
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