Karma/post is a terrible way to rank members because karma comes from videos, photos, news, and reviews as well as posts.
Want a better ratio? Never post ever!
For example the RedBull account has zero posts and 104k karma from news and videos. Infinite Karma! Mmmmmm. FreeskiTV made the mistake of making 1 post to go along with there 600k karma. There might be a account with more karma and zero posts, I just knew the RB account didn't have any posts so I picked it.
When it comes down to it, more karma doesn't necessarily mean a member makes better posts or is a better member but it does mean that they have added a lot of content to the site.