[lovethevoid]

They do use personal information, and YouTube provides creators (and their ad partners) with a lot of personal information. It makes it very easy for a company to note what channels have fanbases that are for eg. 18-24 year old straight males who mostly live in the midwest, are single, play video games, use android phones, likes/dislikes xyz, uses these sites, etc. and advertise things to them.

There are some general ones who won't use targeted personal advertising, but for the most part, this personal information is why you will never see gym supplements being advertised on feminine beauty channels (despite channels being open to the money), or mascara products advertised on a gamer channel (again, despite them being open to the $$$).