This week I stumbled upon this startup : https://www.milesbooster.fr/

I registered.

Basically it is an affiliation program letting you earning points on various marketplaces. At first sight it seems promising: on some website you can earn 1 point for every EUR spent, in addition to the points earned through FB Amex for instance (providing the website in question takes Amex of course). You can then convert your points at a 1:1 ratio into FB miles.

Unfortunately it is in French only but registration does not seem restricted to French people.

Anyone tried already?