The Bing team at Microsoft use FPGAs in production. I was chatting with one of their developers recently who is focussed on that space for them and he mention

The Bing team at Microsoft use FPGAs in production. I was chatting with one of their developers recently who is focussed on that space for them and he mentioned they find they get similar performance to GPUs, but with significantly less power consumption, while affording them the same levels of flexibility for their particular use case.