Why Facebook can't match Ravelry, the social network for knitters.The best social network you've (probably) never heard of is one-five-hundredth the size of Facebook. It has no video chat feature, it doesn't let you check in to your favorite restaurant, and there are no games. The company that runs it has just four employees, one of whom is responsible for programming the entire operation. It has never taken any venture capital money and has no plans to go public. Despite these apparent shortcomings, the site's members absolutely adore it. They consider it a key part of their social lives, and they use it to forge deeper connections with strangers—and share more about themselves—than you're likely to see elsewhere online. There's a good chance this site isn't for you, but after you see how much fun people have there, you'll wish you had a similar online haunt. The social network is called Ravelry. It's for knitters (and crocheters).Ravelry's success is evidence in favor of an argument that you often hear from Facebook's critics: A single giant social network is no fun. Social sites work better when they're smaller and bespoke, created to cater to a specific group.