Buttons advertising the reviewed VPN services. The same bright button spammed about 10 times across the page on every review. Additionally there is hyperlinked text leading to the VPN providers' sites which should be sufficient if a user wants to visit them.
If you search for review site:securethoughts.com you get page after page of search results and all the reviews have those buttons like I said. They link to the provider multiple times on every review through bold, hyperlinked text too so there's no need for the buttons.