The title uses the word "high-tech", while the article uses "Hot startup", I doubt if Yelp can still be classified as a "Hot startup". Answering whether Yelp is truly "high-tech" does not matters since the article makes no assertion that relies on assuming Yelp to be "High-Tech".

The article is selling standard business analysis, packaged as if it was some kind of brilliant visionary insight. This "Retro analysis"completely ignores new streams of businesses that Yelp is getting into such as Food delivery. These typically have much higher revenue albeit at lower margins, than just advertising. Not factoring it is a gross miscalculation. The article also fails to compare Yelp with Grubhub. Which would have produced a much more realistic expectation.

The article reminds me of this video by Steve Jobs discussing how Marketing & Sales end up destroying companies. https://www.youtube.com/watch?v=-AxZofbMGpM