Why is Microsoft so panicked over Google-Yahoo? Time's list of 50 best websites provides an anecdotal answer. Of the 50, 18 rely on Google ads for their income. Only one, UrbanDictionary.com, uses Microsoft ads. Yahoo doesn't fare much better — only brokering impressions for Rate My Professors and its own site on the list, Yahoo Answers. Below, find Time's entire list and how each site apparently makes its money (if it does at all — seven are run by volunteers).

• By the numbers
• Ad-supported:36
• Google ads: 18
• Microsoft ads: 1
• Yahoo ads: 2
• In-house ad sales teams: 3
• Sell goods: 2
• Sell physical goods: 1

• Time's 50 Best Websites 2008
• GasBuddy — Google AdSense and a display ad.
• Howcast — Google Adsense.
• iliketotallyloveit.com — Google Adsense
• Omiru — affiliate accounts with vendors such as Amazon and Bluefly
• PsychCentral — Google Adsense.
• TripKick — ValueClick banner ads.
• Wikitravel — Google Adsense.
• Yahoo! Answers — Yahoo display and search results.
• Zeer — Google AdSense
• Afrigadget.com — run by volunteers.
• AskMen.com — Google search ads and Google AdSense.
• ConcreteLoop.com — Google AdSense
• Health.com — Display advertising, served by DoubleClick, sold by Health magazine.
• PopSugar — display ads, sold internally.
• ProFootballTalk — Sponsored by Sprint, Valueclick display ads.
• Rate My Professors — display advertising and Yahoo contextual ads.
• Serious Eats — diplay advertising from BlogAds.com network.
• The Nest — display ads, sold internally.
• Geni — ad-free.
• MapJack — Google AdSense.
• Mint — affiliate marketing.
• NexTag — sells its own search ads.
• Nymbler — Google AdSense.
• Picnik — sells premium accounts
• Pixelgirl Presents — Volunteer run.
• SearchMe — Doesn't make money.
• TinyUrl.com — Google AdSense.
• Mobaganda.com — Doesn't make money.
• Urban Dictionary — Microsoft display ads, Google AdSense, Amazon Affiliate.
• Cylinder Preservation and Digitization Project — Volunteer-run.
• Hulu — Pre-roll video ads.
• Imeem — affiliate sales, in-house ad sales and video ad networks.
• Kongregate — Google AdSense display ads.
• ffffound.com — Display ads from The Deck ad network.
• Lookybook — Affiliate links to Amazon.com, Barnes & Noble.
• Someecards — Google AdSense.
• WebSudoku — Google AdSense.
• Penny Arcade — Google AdSense display ads, internal ad sales.
• Gaia Online — Sells virtual goods.
• CarbonRally — Volunteer run.
• COLOURlovers — Display ads from The Deck ad network.
• Apartment Therapy — Glam ad network, AdBrite text ads.
• Digital Vaults — Volunteer run.
• Free Rice — Volunteer run.
• HypeBeast — Google AdSense display ads.
• Kiva.org — Volunteer run.
• Net-a-Porter — Sells clothes.
• Open Source Food — Google AdSense.
• Petfinder — Sponorships, display ads, sold internally.
• WikiSky — Donations.

Contact information for this author is not available.