Why is it an argument for an effect being real that a lot of people have personal stories about it? For instance, a lot of people have stories about mentioning a niche interest while using certain software and that interest later appearing in Google results. That can happen for reasons related to statistics and confirmation bias. Consequently, a lot of people have stories. So what? Some software spies, some doesn't, the rumors aren't how we tell the difference, and "scientifically and anecdotally" is a terrible phase, as if those things were of equivalent merit. Lots of people have stories about bigfoot.