"This has happened to me and others I know on many occasions, so I don't believe Facebook's explanation. For example, last winter, my boyfriend told me (in a conversation at the dinner table) about an obscure brand of boots that his daughter wanted for Xmas (she lives in another country). I'd never heard of this brand and never once searched for them. But within days they were showing up in Facebook ads in my feed and that lasted for about three weeks. Coincidence? I think not. "