A lot of the comments here are missing the picture... They may be trying such deals because they just found out that behavioral advertising is ilegal under GDP

A lot of the comments here are missing the picture... They may be trying such deals because they just found out that behavioral advertising is ilegal under GDPR without consent. And also, under GDPR, people should be able to decline without a degraded service. They first tried to place consent in the ToS, and failing that they tried declaring it a "legitimate interest". Except it isn't and a DPA ruled as such. "The cost of doing business" may become significant. So they may be trying this deal because they are screwed in the EU, offering a subscription as an alternative. Except that this too will be deemed ilegal. People saying that they'll sell that data anyway are missing the point: (1) they are not selling data because they aren't stupid, and (2) the EU is making their business model ilegal within the EU.