This is very true, as I've observed with a small community of programmers I founded.<p>I created a FB page called "I Live Prograaming" and played with FB ads, which gave the page about 1000 likes in a short doace if time, a few years ago and the old format for pages worked quite well for a community, which timeline destroyed. We (three others were helping me at this point) discovered that groups are actually exactly what we needed.<p>We started creating groups and each turned into fairly active communities, seeded from our growing page. We found the demography of our groups matched that of our page, which seems obvious but found it interesting.<p>We have many that are secret with hundreds of members - past a certain member count you are unable to change this setting with your member's privacy as the reason against , which makes a lot of sense.<p>Our format is fairly simple: I Love X, where X is anything technical, which began with I Love Programming.<p>Some groups hold over 200 members each and there are groups for most common programming languages and platforms (I Love C is fairly popular).<p>I'm not trying to plug though, I've refrained from linking, but more to show a full picture of what the article refers to.<p>Facebook, for me, had been a great way to build a community based around my passions.