They are for sale https://buygithub.com/product/stars/ so it is very suspicious in this case, when there is a sudden spike, a marketing blog mentioning them.
My personal experience is that most stars on my projects come from empty accounts that star random stuff to avoid getting detected when they star the projects that paid.
My personal experience is that most stars on my projects come from empty accounts that star random stuff to avoid getting detected when they star the projects that paid.