“Don’t it always seem to go
That you don’t know what you got till it’s gone”
– Lyrics by Joni Mitchell from “Big Yellow Taxi” in 1970. (Younger readers, Counting Crows remade Joni’s song in 2002.)

It’d been almost a month since the last major Twitter outage, and those lyrics came to mind this morning when millions of people (and companies) could no longer follow the timelines of those they follow. Twitter users could tweet to their heart’s content, but no one could read what they had to say. Now many users are gamely trying to catch up on 2-3 hours of downtime, checking on what they might have missed.

Depending on how many people you follow, that could be a lot of tweets to cover.

Recent news focused on Twitter being valued at $1 billion. Those valuations, of course, were based upon business analysis, as it should be. Today, there are reports Twitter is negotiating deals with Google and Microsoft to sell them feeds of Tweets into their respective search engines.

But what was the cost of today’s outage to millions worldwide? Consider the businesses who have cut back on customer service staff and let users interact with a live Twitter account. Consider the corporations who use Twitter to promote and discuss their products. What about the numerous small businesses and professionals who use Twitter to promote their services — and themselves? Or the marketers paid to promote businesses through social media?

That’s the business cost. Hard to put a price tag on it. Then there is the social, political and entertainment cost. U2 frontman Bono kicked up a storm on Twitter with a video presented at today’s Conservative Party conference in Manchester, England. Many Brits apparently felt he should not associate with such an event and had rather harsh things to say. Suddenly, that vent was closed and the angry were left without a voice.

On a far more frivolous level, not even the outage could stop Twitter’s current No. 1 Trending Topic — teen sensation Miley Cyrus apparently killed her Twitter account at her boyfriend’s request. Her fans want her back. At this writing, the top topic is #mileycomeback.

There are plenty of people who will laugh and say I need a life when I ask these questions — What did the Twitter outage do to your day? What did it mean for your business?

It meant a lot to Brits, especially in London, the world’s largest market for Twitter users, who suddenly — right or wrong — couldn’t complain about Bono’s video. I’ll bet it also meant a lot right here in Atlanta, the world’s 10th largest Twitter market.

A lot of people don’t understand Twitter, but after today — and other too frequent outages and fail whales on the site — many know they’ve lost something when it’s gone.