I've always had the general sense that "uses uBlock" is a hugely useful advertising signal. On one hand, it means you hate ads and are unlikely to respond to the average crappy banner ad (or phishing attempt). On the other, it means that you're tech savvy and potentially high-income. That's some great info.

(Given all that, why are so many under-ad-space texts so bad? It seems like if you're going to target ad blockers under your display ads you could do better with it.)