BitPay alone has 50k merchants: http://blog.bitpay.com/2015/03/10/heartland-payment-systems-...
Coinbase has 38k: https://www.coinbase.com/about
Gocoin has 5.5k: https://ihb.io/2015-01-29/news/gocoin-announces-5500-merchan...
That's already 93.5k from merely 3 american bitcoin gateways. Add the rest of the world (China, etc) and it is clear there are 100k or more.