Members come and go, OG, new members, trolling members, it happens on every board possible and shouldn't be a top line revenue driver. The investment advertisers make are based on the unique visits and ppc at the content level, not based on the community discussion or activity. There are no metrics that are valuable to an investment in an open public forum. I'm sure this site, like many others, in its infancy had closed registration while it developed it's identity. Most of the originals consider this the good old days because they had to communicate with users who helped form that identity. Once that identity was established, content becomes the priority as that is how you drive ad revenue. You open up the community registration because it's secondary, with the proper controls in place, you now have a retaining user metric. Most advertisers look at demographic (content based), unique visitors, and quite frankly, the total reach of your content (boiled down statistic of "reblogs").
At the end of the day, the main page at HB is much improved then former. It's a clean redesign as if it were a magazine or a newspaper. I