The context for those is still marketing. I too don't understand what's to be gained from a tool like this. If the party collecting the data abuses it to spam

The context for those is still marketing. I too don't understand what's to be gained from a tool like this. If the party collecting the data abuses it to spam you then you simply unsubscribe/block the emails altogether. And of course they know you know you can do this, which gives them incentive to not do that.