How Toxic Are Toxic Backlinks ($4.5k Case Study)?

There is an ongoing debate in the SEO community about the impact of toxic backlinks on a website's ranking. I constantly see it on r/SEO and in the comments of popular SEO blogs. Some people believe that toxic backlinks can harm a website's ranking, while others argue that they have no effect. For example, there is a popular quote from John Mueller, that says:

Even though I wasn't able to find the original source of this quote, it's often cited in blog posts and discussions about toxic backlinks. A lot of people say that "negative SEO" should not be possible since it would be an easy way to tank a competitor, and Google should not allow it.

What I find funny (but not too surprising) is that I have never seen any proof of such claims, for example, a case study. People just repeat what they hear from others, without any evidence to back it up (this is very common in this industry). So, I want to share my own experience with some solid data.

Preamble

For the past 6 years, I have been working on a project that I started from scratch. It's an eCommerce micro-SaaS, which at first was available only as a standalone website. I haven't done any off-page SEO for it, since I was focusing on building the product and the content, and also I actually didn't have enough experience in backlink building at that time, so I didn't even know where to start. So, I have never bought any backlinks, I have never participated in any link schemes, and I have never done anything that could be considered "black hat". However, the website still had some traffic from Google for some low-competition keywords, which was nice.

How I unintentionally acquired several thousand toxic backlinks

So, I knew that I had to start building backlinks to the website, but I didn't even know where to start. I did some competitor analysis with Ahrefs, and I found out that some of my competitors had backlinks from eCommerce stores (which makes sense for an eCommerce SaaS). At that time I was also thinking about making the service available as an app for Shopify merchants, and that's when it hit me: what if I make an app in such a way that it creates a functional page on the merchant's store, and that page will have a backlink to my website (with an ability to opt out of course)? That way I could get a backlink from every merchant that installs the app! You've probably seen a lot of examples like this, such as a "powered by" link in the footer of a website.

That seemed like a bulletproof strategy to me. Of course, I understood that a lot of the stores would be the ones that are just starting out, and their domains wouldn't have any authority, but I thought that it would still be better than nothing, plus some of them could grow into big stores in the future, and a small percentage of them could already have some authority.

I started working on the app, and after a few months, I launched it on the Shopify app store. The app had a very generous free tier (compared to competitors), since its main purpose was to acquire links, not to make money (a mistake that I will regret in the future, but this is a different topic). I kickstarted it with a $4.5k investment in ads on the Shopify app store itself (hence the title of this article), and the app started getting installs. I was very happy with the results, reaching 3k active users in just 4 months (topping at about 5k in another 12 months or so).

Any results?

So, the backlinks started pouring in (several thousand referring domains, awesome, right?), and Ahrefs DR skyrocketed to 70+, but to my surprise, the organic traffic didn't increase at all. I've actually started to lose rankings even for the keywords that I was already ranking for. I was very confused, and I didn't know what was happening. I thought that maybe it was just a temporary thing and that the traffic would come back, but it didn't. Ultimately, I concluded that maybe something in Google's algo has changed, and I should just move on since it's the only thing that I can do.

After some time, I've noticed in the Semrush backlink report, that it marks a lot of backlinks from the app with a high toxicity score. The reasoning behind this was that the links were coming from the same URL pattern (like store.com/apps/my-app) combined with the low domain authority of the referring domains. In hindsight, it makes sense (from an outside point of view it looks just like some low-quality PBN), but at that time I was not ready for any radical decisions (like removing the links), since I was still getting some traffic from Google, and I was afraid that I would lose it completely if I remove the links (especially considering how much I have invested in this whole ordeal; sunken cost fallacy, yeah, I know). So, I decided to just leave it as it is, and see what happens, comforting myself with the thought that those metrics from platforms like Semrush are arbitrary and that Google doesn't use them in their ranking algorithm, especially looking at my 70+ DR in Ahrefs and getting just a fraction of the traffic that my competitors with much lower DR were raking in. Also I still thought that such backlinks could not be bad, I mean, it's not some cheap spammy Fiverr gig, those are real eCommerce stores, right?

Time for drastic measures

After some time, Shopify has forced all developers to move to a new version of their API, which introduced some breaking changes (the nightmare every Shopify dev remembers). The app stopped working completely until a merchant opened the app in their admin panel and clicked "update" to "rewire" some stuff in the DB. But I haven't even collected merchants' emails (like for email marketing purposes), since, well, as I've mentioned before, the primary goal of the app was to get backlinks (I know, I know...), so I didn't have the means to warn the merchants beforehand. It meant that I would lose a lot of users since merchants would not be happy with such an interruption of the service. And even in the case of those who would decide to stay, there would've been some downtime for the backlinks, so they would "blink" in Google's eyes, which could've been a bad signal for the algo (as I've heard somewhere a long time ago; not claiming this is true, this is just what I was thinking at that moment).

So I decided to do what I have been thinking about doing for some time already (considering the Semrush reports) - I've removed the "powered by" links from the app.

No way!

Guess what happened - the traffic bounced back! Here's what it looked like on Ahrefs:

Mind you, no off-page (or on-page for that matter) SEO has been done during this period, so the only thing that has changed was the removal of the backlinks from the Shopify app (i.e. the stores which had it installed). Could it be a coincidence? That both times - the drop and the rise - were just results of some Google algo turbulence? Maybe. But that would be a pretty big one, so I don't think so.

Probably, if a domain already has a lot of authority, it can withstand a lot of toxic backlinks, but for websites with a small backlink mass (like mine at that time), it certainly has a clear negative effect.