>How many hundreds of ads were they shown over two days until they were shown one in the category that confirmed their bias? Refreshing Facebook a few times now

>How many hundreds of ads were they shown over two days until they were shown one in the category that confirmed their bias? Refreshing Facebook a few times now, I'm shown several ads for products and pages I have zero interest in which I don't search for or talk about. And to go even further. How many ads of cat food have they seen in the days prior to their experiment that they did not conciously see but that influenced the "random topic" they chose.