Brave, an ad-blocking web browser with a blockchain-based twist, has started trials of ads that reward viewers for watching them — the next step in its ambitious push towards a consent-based, pro-privacy overhaul of online advertising. Brave’s Basic Attention Token (BAT) is the underlying micropayments mechanism it’s using to fuel the model. The startup was founded in 2015 by former Mozilla CEO Brendan Eich, and had a hugely successful initial coin offering last year. In a blog post announcing the opt-in trial yesterday, Brave says it’s started “voluntary testing” of the ad model before it scales up to additional user trials. These first tests involve around 250 “pre-packaged ads” being shown to trial volunteers via a dedicated version of the Brave browser that’s both loaded with the ads and capable of tracking users’ browsing behavior. The startup signed up Dow Jones Media Group as a partner for the trial-based ad content back in April. People interested in joining these trials are being asked to contact its Early Access group — via community.brave.com. Brave says the test is intended to analyze user interactions to generate test data for training its on-device machine learning algorithms.