From the article: > I’m surprised that SimilarWeb finds the personal browsing data that it siphons off via Stylish so valuable. The data almost certainly feeds

From the article: > I’m surprised that SimilarWeb finds the personal browsing data that it siphons off via Stylish so valuable. The data almost certainly feeds into SimilarWeb’s main product, the SimilarWeb platform, a tool that provides reports on the aggregate usage statistics of websites and apps... But data collected via Stylish will surely be riddled with so much sampling bias that it becomes worthless... A giant stew of miscellaneous, unattributed scraps of data can’t ever turn into a representative sample, no matter how much salt and machine learning you add. I'm not surprised at all. It's important to note that SimilarWeb sells its data to non-statisticians. Imagine this scenario: Marketing analyst has a gut feeling that the product would be popular with millennials on Reddit, but old-school marketing execs barely know what Reddit is. Analyst sneaks a SimilarWeb subscription into the budget. Analyst gets Stylish-based data that is heavily biased towards Reddit. Analyst may know this. Analyst doesn't care. Analyst uses the data to "prove" that the company's users are on Reddit and justify the Reddit ad spend they wanted anyways. Campaign is a success. Pretty much everyone wins (kind of): Reddit users get more relevant ads. Analyst advances their career and reputation. SimilarWeb gets paid. Stylish extension can be maintained and polished. SimilarWeb maybe even affords to hire for their security team, who makes sure that the data is anonymized at rest. At the end of the day, adtech is a beast that grows because it tells people what they want to hear, and remains silent when it can't find that answer. p-hacking and survivorship bias are the way of the world. This isn't necessarily a bad thing. But... if this sounds like a bubble to you, all I can say is that you should diversify your holdings outside of tech stocks.