I always make sure to "like" political opponents from across the aisle. I liked Donald J Trump, Hillary Clinton, Bernie Sanders... But I only did that to see w

I always make sure to "like" political opponents from across the aisle. I liked Donald J Trump, Hillary Clinton, Bernie Sanders... But I only did that to see what they were saying, given primary sources are often better than the media. It doesn't mean I "like" them. Do all of Trump's twitter followers like him? I don't think so... Really, it's the "likes" of more obscure pages that provide demographic signaling. I can infer a lot more about someone who likes a bike repair shop in Portland than I can about someone who likes yahoo.com. For that reason advertisers are unlikely to be targeting people who like a top-200 website like yahoo.com; the top 200 websites are already noise. Someone liking one is meaningless.