This brought to my mind to do something similar for digital advertisement, i.e. collecting various ads on the web and (automatically) label them through their metadata. I’m not quite sure yet we’re this could go. I imagine different categories: SaaS ads, video game ads, company ads, e-commerce ads, and so on, all categorized by company, date, site, etc. You could then see how ads changed for a specific tag/category over time or how ads for a single company, say SAP, changed.