The Reddit voting widget.
http://reddit.com/buttons
Widgets · Social Sharing
Get access to data on 1,340,423 websites that are Reddit Customers. We know of 214,349 live websites using Reddit and an additional 1,126,074 sites that used Reddit historically and 138,400 websites in the United States.
Get a list of 1,340,423 websites using Reddit which includes location information, hosting data, contact details, 214,349 currently live websites and an additional 334,982 domains that redirect to sites in this list. 1,126,074 sites that used this technology previously and 138,400 websites in the United States currently using Reddit.