I think both
Stoya, and
Jacky St. James do an amazing job with tumblr. (Siri used it effectively but tumblr took it down, says my girlfriend)
It's a good blog platform if you are writing from a consistent personal viewpoint, your persona as an adult film star or a brand name pornographer, and you are reaching a younger or female audience - but you always need to keep in mind the platform's terms of service may change or ban you, and you need to have a back up of your content and a plan to move to something stable longterm.
It's probably not a good place to have a spam blog.