That's essentially my rule as thumb, alongside some personal grammar peeves. This was thrown around, but I've promoted a couple in one day. https://hubski.com/pub/218639#h386361 Just scroll through there from time to time since that's seemingly the only place for reliable new traffic. Looking into their profile is how I've gone so far. Also, there are people who have been on Hubski more than a year, yet haven't reached a full spoke yet - meaning they can't post. Sometimes it's worth looking. Even just a friendly comment from a new user - enough to know they're not a spam bot, really - would get a promotion from me. I can't remember what the limits are, though - how many people can you promote, again?
mk: I have no idea where the extra height comes from. Looked through the page with Google Developer thing: none of the elements increase height but <body> itself, for no apparent reason. Might be due to the <iframe>, but that would be your guess. Also, I'm stealing the tip of increasing font weight on lower-width devices.