Developer Mike Bithell announced on Twitter that Thomas Was Alone sales have suprassed 1 million copies sold.

https://twitter.com/mikeBithell/statuses/459752387578982400

While the game was originally released for PC in 2012, sales really started picking up when Curve Studios and Bossa Studios ported it to PlayStation 3 and PlayStation Vita last April.

According to Bithell, the majority of game sales spiked when it discounted, in a bundle or in through other promotions.

https://twitter.com/mikeBithell/statuses/459752989990088705

Bithell also explained that the 1 million figure does not include PlayStation Plus downloads, which would have increased the numbers significantly.

https://twitter.com/mikeBithell/statuses/459753914884444160

 http://www.dualshockers.com/2014/04/26/thomas-was-alone-supasses-1-million-sold-copies/

Nice the game is really fun and creative. I got it for my vita. Thanks PS+. They totally deserve this.

It's always good to see small developers become successful. I bought Thomas Was Alone with the money from the PSN rebate promotion.

Well deserved. Awesomely awesome game.

If the developer made $1 per copy (discounting everything) then there already made 1 million dollars ;)

I'm glad they're seeing success, especially since it's connected to my platforms of choice. I hope to see more indies and indie success stories in the future.

Awesome to hear, absolutely loved that game on my Vita. Was awesome to listen to Bithell talk about how he made the game as I played with the dev commentary.

Just remembered I got this in the latest Humble Weekly sale. Gotta check it out!

this game was awesome. Same people who did a clone in the dark right? if so this is the company that completely changed my mind on indies

Not the same developers.  Curve developed Stealth Inc. but they only published Thomas Was Alone.  They publish indie games on Sony platforms, including Lone Survivor.