It will be an uncanny valley. Better reading 50 shades of gray than playing with a Boston Dynamic doll. It would surely sell though, people are actually buying expensive dolls, I'm sure some of them would be tempted by a hugdroid.

I think social acceptance is likely to be the bigger holdback.

50 shades is an interesting example of this effect. Women supposedly weren’t interested in this area (not my personal experience), but get enough social acceptance and even an appallingly badly written book becomes a popular success.

Sex robots will face the same “icky” effect, but all it will take for them to become popular is social acceptance via a breakout event once they become good enough.

I think it's a deeper personal reaction, not a social thing, you're confronted with something close to a human that is not one. It won't work unless for a few people.