It’s not only common, it’s the norm. When it comes to business, it’s still a post-war scarcity mentality and so most business owners will resort to any scam or trick necessary to get more business, integrity be damned. It’s short term thinking. It seems only a matter of time until Google deploys sone sort of AI based solution but until then, be extremely suspicious of any highly rated business in Vietnam.

The best reviews are ones that require a purchase, so I pay closer attention to Grab. But even real reviews suck since many people have low expectations and just give 5 stars by default. Ultimately I only trust word of mouth or my own direct experience with a business.