The biggest threat to privacy today isn't from governments, corporations, hackers or terrorists. It's from people who use the latest social-media technologies to broadcast events of their lives, from minutiae to rites of passage, so that anyone can see them. It's the new age of lifecasting, and most of us will wind up taking part in it, voluntarily or not. As consumers take part in the trend, marketers are starting to adopt it, too.

Lifecasting today differs from the updates people would post online during the past decade, such as through personal Web pages (a la Yahoo! GeoCities), blogs, podcasts and recorded video. With lifecasting, barriers that existed previously - from technological hurdles to the time required to produce content - have all but vanished, allowing for effortless participation and immediate content distribution. Lifecasting's emergence can best be exemplified by developments in three channels: social networking, mass messaging and live video streaming.

Social Networks

It's not necessarily such a bad idea for people to share life's little moments with friends, but online, it's easy to stretch the definition of friendship too far. Whether consumers actively are seeking to show their credibility within a community by racking up buddies or they just feel bad turning down requests from people who are barely acquaintances, those inner circles quickly start to feel much less intimate.

MySpace helped make lifecasting easy on social networks, with most active users participating in public profile messaging, blogs and group posts to friends. But Facebook emerged as the embodiment of social-network lifecasting, as its default settings allow any update users make on the site (adding a friend, writing on a message board, joining a group) to be shared with all of their friends.

Marketers have started to try to one-up each other by creating viral applications for these sites; with every new application a consumer embeds, it's exposed to a much wider circle. A new form of math is emerging so marketers can understand the value of hooking one consumer, since that can lead to hundreds or even thousands of others engaging with the brand in some way.

Mass Messaging

For the past several years, blogging was the epitome of lifecasting channels. There was a catch, however: To get readers, bloggers needed to think about what they were writing. That doesn't mean every blog created was worth reading, but it did discourage the sorts of pointless updates friends would write each other through instant messaging. And the fact that such posts are public made some people think twice before posting them.

Enter Twitter, which allows users to easily post public updates about what they're doing via the Web, instant messenger or mobile devices. Posts are capped at a length of 140 characters, making them so short that it's common for them not to say anything at all. Recent posts from my own network included, "I wish I had an Australian accent," "Drinking time!" and "Is it wrong that I like McDonald's breakfast burritos?"

One thing all these posts have in common is that they're written by some of the most talented bloggers and writers I know. Just imagine what others are posting!

Not surprisingly, there are alternatives to Twitter for those into the live-text phenomenon. Pownce, Jaiku and Tumblr are a few of the other entrants today, and they all aim to tap into the network effect to make their services more useful and more a part of people's daily lives. Marketers and publishers are starting to come on board, as these are perfect vehicles for brief updates such as deal or sale alerts, links to news, or reminders for live events like a TV show airing.