Game Distribution Platforms

I am aware of the following online videogame distribution platforms.

These platforms allow you to create an account, buy a game, and keep track of it in your account. You can download it later, even after a few years, by logging in to your account. As such, they are different from an online-store, where you can only download it at the time you buy it, but not later.

Note that many platforms provide keys to download bought games on other platforms as well. In particular, many platforms provide Steam keys.

Number of titles is measured at June 2015, by counting the number of Mac games, excluding downloadable content (DLC).

Most distribution platforms take about 30% of the cost. Humble Bundle only keeps about 10%, although that excludes about 6% for transaction fees, and another 10% for charity. For a slightly more recent overview, Mana marketing blog posted a 15+ indie-friendly platforms guide. Apple is most expensive with 30% (15% for subscriptions after the first year) and $99/year. Steam requests a $100 up-front fee to prevent fake games submissions, which is re-imbursed after the game sells $1000 or more. Gog offers an option to pay royalties in advance to developers, in exchange for a fee of 40% instead of 30% (until the royalties have been paid of).

The prices of all platforms are usually the same, although in particular Steam often has deep discounts (up to 80%) during summer and Christmas season. Humble Bundle has weekly bundles which are 'pay what you want'.

Defunct Platforms

 * Impulse:merged into GameStop
 * Direct2Drive:merged into GameFly Digital
 * Playfire:merged into Green Man Gaming
 * Games for Windows Marketplace:merged into Xbox Live

Other Stores
Regular stores, like Amazon.com may also offer direct downloads.

Many publishers, like Telltale or Auran, offer their own digital download solutions.

G2A.com offers a marketplace, seemingly for second hand games (though I'm not clear how this works, it's not always possible to transfer the usages rights between accounts on game distribution platforms).