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...

VS

OpenX
1,474,014 websites

OpenX costs money

http://openx.com

OpenX is one of the world's leading providers of digital and mobile advertising technology, enabling businesses to manage and maximize their ad revenue. OpenX products, including OpenX Enterprise, OpenX Market and OpenX Lift provide a compr...

Market Share by Top Websites

1 OpenX 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 OpenX in all segments.

Websites Categories

1 OpenX has better usage coverage in more websites categories. Including Arts & Entertainment, Science & Education, Computers Electronics & Technology, Games and 20 other categories.

2 Google Publisher Tag hasn't got a lead over OpenX in any websites category.

Geography

1 OpenX is leading in most countries, including United States, Russia, France, Taiwan and 160 other countries.

2 Google Publisher Tag is leading in Japan.