Google Publisher Tag
545,414 websites

Google Publisher Tag is free to use

https://support.google.com/dfp_premium/topic/28788?hl=en&ref_topic=28149

Google Publisher Tag (GPT) is an ad tagging library with which you can dynamically build ad requests. GPT takes key details from you such as ad unit name, ad size, and custom targeting, builds the request, and displays the ad on web pages o...

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SMART AdServer
961,218 websites

SMART AdServer offers both free and paid options

http://www.smartadserver.com

Smart AdServer SAS develops and markets one of the main ad serving technologies for the management of online campaigns for media agencies and publishers. Created in 2001, the company Smart AdServer, has 300 customers for 1600 sites span...

Market Share by Top Websites

1 SMART AdServer is leading in Top 10K Sites, Top 100K Sites, Top 1M Sites and The Entire Web.

2 In terms of market share, Google Publisher Tag is clearly lagging behind, losing to SMART AdServer in all segments.

Websites Categories

1 SMART AdServer has better usage coverage in more websites categories. Including Arts & Entertainment, Science & Education, Games, Computers Electronics & Technology and 19 other categories.

2 Google Publisher Tag is leading in Business & Consumer Services.

Geography

1 SMART AdServer is leading in most countries, including United States, Russia, France, Taiwan and 158 other countries.

2 Google Publisher Tag is leading in Japan, Cuba and Haiti.