Meta Description
16,590,838 websites

Meta Description is free to use

http://moz.com/learn/seo/meta-description

Meta descriptions are HTML attributes that provide concise explanations of the contents of web pages. Meta descriptions are commonly used on search engine result pages (SERPs) to display preview snippets for a given page.

VS

P3P Policy
2,537,460 websites

P3P Policy is free to use

http://www.w3.org/P3P/

The Platform for Privacy Preferences Project (P3P) enables Websites to express their privacy practices in a standard format that can be retrieved automatically and interpreted easily by user agents. P3P user agents will allow users to be in...

Market Share by Top Websites

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

2 In terms of market share, P3P Policy is clearly lagging behind, losing to Meta Description in all segments.

Websites Categories

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

2 P3P Policy hasn't got a lead over Meta Description in any websites category.

Geography

1 Meta Description is leading in most countries, including United States, Japan, China, Germany and 162 other countries.

2 P3P Policy hasn't got a lead over Meta Description in any country.