I find it's a bit harder for niche guilds and small, starting up guilds, even on a RP server, but it's always been a struggle to create and build up a guild, especially with a specific focus. There are things I dislike about the guild leveling and achievement system too, but we don't use any of that for our guild recruitment.

My main guild is a heavy RP guild and we focus on that in the guild finder and our website. We look for people who can read the directions, come RP with us, and have patience before we admit them into the guild. We make it clear we don't do progression stuff; we have our partner guild for that, and the arrangements have remained unchanged after Cata.

My other guild, where I raid (even on my main, who is in the RP guild as playing with friends > guild achievements) doesn't advertise and is mainly grown by word of mouth and by, again, seeing how patient people are when it comes to their laid back admittance process.

The ideas in this article for promoting guild achievements as a way to do things as a guild together is a nifty one. I would like to do a lot of old school instance stuff for the guild achieves, because it could be a really handy way of getting folks to do stuff together as a guild, which is part of the point.