Yes and no. He was probably talking about those SEO spammers that go around posting how great something/service is in blog comments, forum posts, paid blog posts,etc, with link drops. This got so bad Google started penalising websites by reducing their presence in search results, based on the quality of inbound links.
Companies also send free products to a range of Vloggers and Bloggers, in hope to get them to write or post video reviews. Some also pay for this on top of the free product if their website or channel has a lot of visitors / viewers. If you look at many youtubers these days, with 100k + subscribers, they will often do reviews on products. At least some do say when they are doing this, and whether or not they are being paid extra to give a review. This all apparently helps with SEO.
I know someone who has a youtube channel with a decent subscriber number, and they get contacted all the time by overseas companies (usually out of asia) wanting to send them products for 'reviews', and a link back to their website for SEO benefits.