Comment by dchichkov

I think it went 'mainstream' around 2007, with Hinton's TechTalk at Google http://www.youtube.com/watch?v=AyzOUbkUf3M And even being pretty far from the ML/AI community at the time, I remember playing with Bengio's GPU based Theano Deep Learning Tutorial at around 2008/09. What had happened right now is just that it had finally started beating SVMs consistently and is fast enough to be used for practical purposes.