Stacks becomes understandable after its explanatory subhead, but the visitor must decide whether it is primarily a bookmark manager, knowledge workspace or AI assistant. The site names students, researchers, creators, builders, lifelong learners, founders, marketers, knowledge workers, teams and businesses. Its jobs are concrete: capture links, notes, files and media; retrieve them through natural-language search; connect ideas; and share collections. Pricing adds anchors of $89/year, $199/year and $349/year, while comparison pages support self-service evaluation. The remaining gap is attributable trust: the homepage says it is trusted by 5,000+ people, and structured data reports 4.8 from 12 reviews, but visible pricing testimonials lack names or roles. Choose one primary audience and map each plan to a specific use case.