OP here. It's not an ad at all. There is a lot of stuff there, not just the Rack. I even wrote about Wi-Fi optimization, the tools I used, how much I paid (I mean if it was sponsored, why would I pay for it).
Second, my cameras were dying, I had to replace it, and I had to make a choice. A friend of my who use Unifi cameras was very happy, so I thought that's a good reason to start using Unifi.
Anyway, both of these, I wrote in my blog post.