"I mean, how difficult is it for Yelp to catch this?!?"
The mistake you're making is assuming Yelp:
* Wants to "fix" this problem.
* Isn't actually complicit in this problem as a means to incentivize small business owners to sign up and pay for Yelp to help "manage their business profile".
And the second mistake is (if they did care) thinking this wouldn't just result in an arms race. IMHO we want easy to spot fake reviews. I want flash to come back. It was so easy to block annoyances in that day. Now we have HTML5 popups.
I assume you're talking about it being easy for the consumer. There is no way I would know that the same college kid copy pasted a pic from a Flordia Zilliow listing to out on a home renovation review but it's trivial to find for Yelp. So I understand the sentiment, but at least to my untrained eye, I just glance at reviews and take them as real as long as a dog walker is not mentioned at a sushi restaurant, which means they are too hard to spot for me.
The mistake you're making is assuming Yelp: * Wants to "fix" this problem. * Isn't actually complicit in this problem as a means to incentivize small business owners to sign up and pay for Yelp to help "manage their business profile".