Current model
The free tier may show ads on selected browse, search, and safe concept-page surfaces when ads are explicitly enabled. Premium removes those ads and unlocks the existing premium study-power features described on the Pricing page.
When advertising is enabled, Open Model Lab uses manually placed Google AdSense units only. The current architecture is manual-first and does not rely on Auto ads as the primary mode.
The intent is simple: ads can support public browsing without interrupting the live science-learning interaction. Before approval and explicit activation, the ad system stays dormant and renders nothing.