A friend recently ask my opinion on how he could spread the word about a new service. He was considering emailing people and posting notes on Facebook, among other things. After offering some suggestions for posting content to various online outlets (flickr, website, twitter, vimeo, linkedin, etc.), I thought about push vs. pull. Most people want to go out and tell (or yell) about what they have to offer...understandably, they're excited about sharing something new. And, while you can generate some results pushing your message with email, unsolicited ecards, etc., it's not the most effective way to get the word to spread. The best way is to allow yourself some time and create a bucket load of fabulous content that will garner some attention. Then, leak it out to some close friends, give some of your product away for free and give people access on as many relevant outlets as possible. Once you have a fan base, ask them if they would care for an occasional email update of your goings on. Repeat.
While it's far easier to hit send on an email blast, the harder stuff almost always works better and longer.