Google's John Mueller was asked how Google detects and determines if a piece of content is written as a guest post? John said "we use lots of different signals to try to figure out what might be a guest post." He added, it is not just that the anchor text makes the guest post problematic.
At the 28:19 mark into a video hangout with John Mueller from a couple of weeks ago, John was asked by Qamar Zaman "So how does Google determine? And like you said, if it's a good anchor text, use it. Now if it's a guest post, and Google does not know whether it's paid or not, how will Google then determine that take this link or burn this link? What is the answer so we are safe from all the angles?"
John first responded that you need to nofollow links in guest posts, like you would for any advertisement. John said "I mean if it's a guest post, then it's a guest post. And our guidance for links and guest posts is that they should be nofollow. So if you're writing these guest posts to drive awareness to your business, I think that's perfectly fine. I would just really watch out to make sure that the links are no-follow. So that you're driving awareness, you're talking about what you're doing, you're making it so that users can go to your page. But essentially, it's an ad for your business. So from that point of view, I would just make them nofollow."
Then John didn't really answer the question on how Google recognizes what is a guest post. He just said Google uses many signals for this purpose. John said "with regards to guest posts in general, like how does Google recognize guest posts, I think that's tricky because we use lots of different signals to try to figure out what might be a guest post, and how we might need to handle that. But it's definitely not the case that it's just like the link anchor text is what makes it problematic."
Here is the video embed:
Here is how Glenn summed it up with more commentary from Lily Ray...
Makes sense for guest posting… I’m sure there are many patterns google can spot there. But I’m thinking more about pages where maybe 5-10 brands are mentioned with a homepage link (paid placements) which *appear* natural but actually cost the brand a ton of $$$ behind the scenes
— Lily Ray 😏 (@lilyraynyc) October 29, 2021
I have no idea, I assume if it’s a high-quality, authoritative website that the links count for something. But just to reiterate, I do not dabble in paid linking at all (since the Penguin days at least 😛). Just asking the questions my clients (relentlessly) ask me.
— Lily Ray 😏 (@lilyraynyc) October 29, 2021
Forum discussion at Twitter.