Pretty much. Ads tell me that something exists. I don't entirely reject products whose ads I happen to see, but I do rate them inversely proportional to the scope of their claims.

And it's not just obvious ads. You can't trust online customer reviews, because there's an industry devoted to spamming them, both positively and negatively.

And you can't trust third-party reviews, because they're often disguised press releases. Or biased by payment. For example, I've been told that many sites that review VPN services basically auction their rating slots.