Were you using an incognito/private mode in your browser?
They're not perfect in terms of keeping you totally anonymous however you shouldn't have pop advertising come up in your browser or receive emails after a search in that mode.
Also if you have a booking.com account with Gmail and use the Chrome browser there is a good chance you'll get an email relating to a search on the site, same with TripAdvisor I believe. Shouldn't happen when searching in incognito mode though.