At least if I get an advertisement I immediately understand the biases behind whoever served it to me, with stuff like reddit or blogs I can never be sure how astroturfed it is, or whether the people reviewing things even know what they are talking about.

I'm not a proponent of advertising in the modern sense, but it's probably the least dishonest way that companies pay to promote their product. Professional reviewers are a good medium but it takes time to find those in a new space where you're not sure if their standards and preferences match yours