It is just that, despite Twitter's strong influence in the media and public consciousness, it isn't worth nearly as much as Facebook.
The reasons for the difference in value are quite clear when you look at the rest of the numbers. Twitter's revenue for full-year 2012 was US$317 million versus Facebook's US$5.49 billion.
According to Bloomberg, Facebook's jaw-dropping listing price valued it at an earnings multiple of 26 times revenue. Twitter will be asking investors to buy in on a multiple of 28.6 times revenue.
Bear in mind that normal companies are valued in single-digit multiples or maybe early to mid-teens if they have growth potential.
In terms of valuing these companies on the strength of user numbers - as they used to do in the late 1990s before the dot.com crash - Facebook also wins hands down.
Facebook has a staggering 1.16 billion monthly users - a good chunk of the world's population. Twitter has a more modest 220 million monthly users.
Of course many Twitter users are far more heavily engaged - sometimes to the point of being connected every waking moment. But Twitter is already copping it from the dot.com sceptics on Wall St who see it has a long way to go to turn heavy use into profit.
Most of the revenue Twitter and Facebook generate is advertising revenue. Although some of it also comes from on-selling data - information which you probably think of as yours but which (if you publish on either of these two sites) you probably shouldn't.
Twitter is a very uncommercial sort of platform. That's been part of its appeal. It doesn't have the glossy look of a Facebook page on which it can embed advertising.
Twitter offers more subtle ways to plug products. It sells promoted tweets that may occasionally pop up in your Twitter feed. Or companies can pay to have their Twitter accounts promoted as especially highlighted trending topics along with the other genuinely popular topics of the day.
Or they can pay to be included among the accounts that Twitter recommends its users to follow. The thing is that Twitter does not yet make a profit - it posted a net loss of US$69.3 million in the first six months of 2013, compared with a net loss of US$49.1 million in the same period a year ago.
So investors have to have faith that the site can be dramatically commercialised over the next few years without turning users off - and on to some other fashionable new social network.
That will be a challenge.
Facebook and Twitter are really quite different. Facebook is a scrapbook and diary for sharing with friends and family. We put pictures of our kids on Facebook, we feel we know who is seeing them. We don't do that on Twitter. It is less personal.
On Twitter we share media links. We also make quirky social observations and proclaim political and other views - then we have polite arguments. At least that is my experience. I enjoy it.
If you don't like wading through a mass of unfiltered personal opinion on Twitter then just don't follow individuals. Following media organisations is a great way to create a personalised news wire service. Every story the Business Herald produces goes out on Twitter - @nzheraldbiz should be a mandatory follow. Was that embedded promotion subtle enough?
What makes Twitter stand out from the social media pack and gives it an edge over Facebook is the speed at which an idea, comment or picture can travel through the network and - if popular enough - be picked up by mainstream media.
Okay, that piece of vital information might turn out to be a feud between pop stars or a TV personality accidentally tweeting something sexist, but still, the speed at which news travels through Twitter leaves Facebook for dust.
In a serious event - such as during the Christchurch quakes - the directness and openness of Twitter make it invaluable.
Twitter is far more of a media service than Facebook. It is a content curator with the world's biggest comment section.
And of course for all that worthiness, Twitter panders brilliantly to the egos of its users.
The people you link with on the site are not called friends or connections, they are your followers.
The genius is that everyone feels as if they've got their own personal cult following. Or at the very least an audience for their opinion. Twitter gives you your own megaphone and soapbox and a chance to offer up your unique take on why the end is nigh.
Twitter's growth may be slowing - as the market analysts warn - perhaps because there is an upper limit to the number of people in the world who want to engage that deeply in public conversation.
But the end is far from nigh for Twitter - it is just getting started. Whether it makes money on Wall St is another issue. One that is sure to be trending on the site over the coming days.
On Twitter: @liamdann
