Yup, for advertising visibility sure. Rather than steemit burn the promo to trending, it's individuals that are making money from being paid for their votes to advertise content. So free votes don't matter, it's all about paying for advertising, since why give someone free advertising when you can charge them for it ;) And they make money by buying the vote too, not just from potential people giving votes freely afterwards... But then why does anyone give their vote freely? Reciprocal potential to get voted on as well on their own posts?