Discogs

Discogs (short for discographies) is a database of information about audio recordings, including commercial releases, promotional releases, and bootleg or off-label releases. Database contents are user-generated, and described in The New York Times as "Wikipedia-like". While the site was originally created with the goal of becoming the largest online database of electronic music, it now includes releases in all genres and on all formats.

History
Discogs was started in 2000 by Kevin Lewandowski who worked as a programmer at Intel. It was originally started from a computer in Lewandowski's closet and was limited to electronic music. By 2015, Discogs had 37 employees, 3 million users, and a monthly traffic of 20 million visits.

In late 2005, the Discogs marketplace was launched.

In July 2007, a new subscription-based system for sellers was introduced on the site, called Market Price History. It gave premium users access to the past price items that were sold for up to 12 months ago by previous sellers who had sold exactly the same release (though 60 days of information was free). At the same time, the US$12 per year charge for advanced subscriptions was abolished, as it was felt that the extra features should be made available to all subscribers, now that a different revenue stream had been found from sellers and purchasers. Later that year, all paid access features were discarded and full use of the site became free of charge, allowing all users to view the full 12-month Market Price History of each item.

Marketplace
The Discogs Marketplace is modeled similar to Amazon and eBay where sellers offer items for sale and a fee is charged on the sold item.