Just ask someone on the social media team how many entries they got when PC gave away a code to get Red/Blue/Yellow on the virtual console.
Yeeeeeah, that was a horrendous nightmare of bureaucracy. Such a simple idea, so not easily executed. Still, I wouldn't be opposed to facilitating another give-away, despite the headache that it was last time. I even have another idea in mind... but more on that later.
Give-aways and incentives aside, what keeps people coming back is an active community. While PC is certainly an active place, I just don't think we've adapted to the trend that internet communities are headed in quite yet. This place has a loyal following of members (myself included, of course), and while I'd love to see more growth of the forums... don't you think smaller, forum-based communities are kind of on the decline? When you've got giant places like Reddit to quickly post questions and discuss things until your heart's content on any content, Facebook to share your moments, and Twitter to post about your day... what's left for the smaller forum communities?
I think we're making giant steps in the right direction with our extremities: Daily, Facebook, Twitter, YouTube, and Discord. I feel like maintaining presence and growing with these extensions of PC is critical, and we're still doing just that with them - growing. However, I agree with Gavin, those extensions alone won't save us entirely. While I certainly don't think PC is really going to disappear anytime soon, we do need to work on features that are uniquely us. We've always been such a warm, welcoming bunch in the fandom. We are unique, and I think we're more than capable of creating a better community - maybe not necessarily a better forum.
Just my $0.02, of course.