If you don’t rely on advertising (speaking directly to possible customers) then you have to work with journalists other middle-men, whose tastes might not reflect those of your customers, or you have for a network to build, which might be too slow. Possible grateful future customers loose out here too.
If I see a place that has 100+ 5 stars on tripadvisor/yelp I'm much more likely to go than if I see an advertisement, because at that point I know a reasonable number of actual people have gone and liked the experience.
I typically dismiss any claims an advert makes as total bullshit because adverts are lying to you the majority of the time. In the case of a restaurant it might work if you're advertising that you're newly opened, but otherwise I'm wondering why people aren't being pulled in when they look on sites like tripadvisor/yelp.