As others have pointed out, it's an advertising technique called retargeting. Here are some of the technical details of how exactly it is done(Facebook's implementation might differ somewhat from this, but overall concept is same) /* DSP - Demand side partner (Entity which works with someone who wants to show their ads) SSP - Supply side partner (Entity which works with some who have potential space on web to show ad…
It's weirder that that. I was notified via a Facebook ad that my Navionics subscription to charts from Asia expired. I only use Navionics as an ios App.
That's not weird. Navionics presumably had your email address. They then likely uploaded that as part of a list of customers into what FB calls a "Custom Audience List" and promoted some post to that audience.