Facebook Advertiser
3,065,817 websites

Facebook Advertiser costs money

https://www.facebook.com/help/435189689870514/

Facebook Ads Advertisers.

VS

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...

Market Share by Top Websites

1 Facebook Advertiser 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 Facebook Advertiser in all segments.

Websites Categories

1 Facebook Advertiser has better usage coverage in more websites categories. Including Computers Electronics & Technology, Lifestyle, Food & Drink, Arts & Entertainment and 19 other categories.

2 Google Publisher Tag is leading in News & Media.

Geography

1 Facebook Advertiser is leading in most countries, including United States, United Kingdom, Brazil, Canada and 161 other countries.

2 Google Publisher Tag is leading in Cuba.