Here's an alternative theory: Campari is actively campaigning via multiple channels.

While difficult to prove or test, it's possible that there is both a facebook ad campaign as well as some real-world campaign going on at the same time. Real-world being either forms of visual advertising that 'primed' you to also talk about it, or perhaps (attractive) people hired to buy/pitch Campari in bars that you may have overheard. Apparently that's a thing.

Basically, Baader-Meinhof strikes me as something that any advertiser who knows about it would actively use to improve their advertising.