MSN Ads
32 websites

MSN Ads is free to use

http://bingads.microsoft.com/

Show ads on Bing. Display your product or service to as many as 151 million potential customers.

VS

Open AdExchange
8 websites

Open AdExchange is free to use

http://www.openadex.com/

New Danish website is now live: openadexchange.dk ... Targeted ads from Open AdExchange will provide you with additional earnings on top of your existing ...

Market Share by Top Websites

2 In terms of market share, MSN Ads is clearly lagging behind, losing to Open AdExchange in all segments.

Websites Categories

1 MSN Ads has better usage coverage in more websites categories. Including Science & Education, Computers Electronics & Technology, Finance, Food & Drink and 8 other categories.

2 Open AdExchange is leading in Jobs & Career.

Geography

1 MSN Ads is leading in most countries, including United States, Bulgaria, Canada, Czech Republic and 6 other countries.

2 Open AdExchange is leading in Denmark, Pakistan and Sweden.