If you're a VPN company, it's actually cheaper for you to own the sites and populate them with your own product than it is to pay a site for placement, especially if you own four or five VPN brands. Heck, sometimes, they don't even acquire sites. They just start them and spend money to get them to rank well.
I don't trust review sites in general (even if they don't contain paid recommendations, they still rank by which affiliate will net them more money), but I /really/ don't trust sites that cover or rank VPN providers. Personal VPNs as they are pitched to consumers are just shy of snake-oil, and almost all the content written that touts them is revenue driven.
Background: I previously helped start and worked for a VPN provider.
Say you want a new pair of headphones. You'll probably do something like this.
1. Search Google & look for forum/reddit threads talking about specific brands.
2. Look for those brands for further reviews, feedback, and price comparisons.
3. You will come across a review that has links to the "best price".
4. By clicking that link if you purchase that product then, or within 15-30 days (depends on the affiliate agreement) the affiliate will earn commission.
That's why big corps work with media companies. They make hundreds of thousands per month via affiliate commissions alone.
This induces a large amount of biases as media sites always recommend their affiliates over non-affiliates.
If there's a relationship with a vendor—especially in articles that review and compare different services—it should be obvious what that relationship is. Online tech publications and review websites are some of the worst offenders these days.
PrivateInternetAccess, a major VPN service was acquired by the same company for 95M.
A VPN review site is worth more than most VPN services it promotes due to insane $CPA they pay to these types of sites, that masquerade as "security exports" while in reality ran by marketing people.
Look at their staff: https://www.vpnmentor.com/about-us/
Every "favorite" VPN is a property they own, except for the sole NordVPN guy.