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

Meta http-equiv
16,540,472 websites

Meta http-equiv is free to use

http://www.w3schools.com/tags/att_meta_http_equiv.asp

The http-equiv attribute provides an HTTP header for the information/value of the content attribute. The http-equiv attribute can be used to simulate an HTTP response header.

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, Meta http-equiv 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 Arts & Entertainment, Games, Food & Drink, Lifestyle and 8 other categories.

2 Meta http-equiv is leading in Computers Electronics & Technology, Science & Education, Health, Business & Consumer Services and 8 other categories.

Geography

1 Meta http-equiv is leading in most countries, including United States, China, South Korea, India and 109 other countries.

2 Meta Description is leading in Japan, Germany, Russia, United Kingdom and 47 other countries.