Facebook will hit the boards this week in the U.S, with their float on the stock market crowning Mark Zuckerberg as one of the richest 28 year olds on the planet, if not in Earth’s history.

Congratulations to Mark on this, but if you’re  looking to buy Facebook stock post IPO you might be wondering: how is Facebook travelling here in Australia?

Well, if size counts, they’re huge. With more than 479 million Total Visits in April 2012, they’re the number 2 site in the country, a position they’ve held for more than three years.

Holding court in the Hitwise Social Networking category, they’ve been ranked first for 36 of the last 36 months. In Australia right now, it’s only Google that see more of us on a daily basis.

In April, Google saw 623,491,085 Total Visits, Facebook 479,897,966. Big figures and hard to make sense of – until you bring Australia’s internet population into account.

Australians were 30% more likely to visit Google than Facebook on any given day

Estimating the current internet using population at 19 million, this suggests Australians were 30% more likely to visit Google than Facebook on any given day, 1.1 visits per day for Google to 0.84 for Facebook.

However, given their different offerings, it’s not the frequency that might help you decide to buy Shares, but the future. We can’t predict the future, but we can look at the trends and behaviours in historical data.

Over the past twelve months, Google usage has trended up, wherease Facebook usage has trended down.

Combine this with the congestion that new players such as Pinterest have created and Facebook have actually under performed their sector, as seen below. Hitwise’s Social Networking & Forums category grew by 5.57% in April 2012 relative to April 2011 – but Facebook shrunk 6.28% in the same period, for almost a 12 point spread.

Also, the Tyranny of Distance appears to be still affecting Australia, although it’s unlikely Professor Blainey had this in mind when he wrote his book .

Viewing Facebook usage by States, it’s intuitively those with the largest population with the lion’s share.

However, if you index this to the population, we see that Victoria and the ACT are under represented. Victoria is under by almost 10% and ACT almost 20%.

Furthermore, both Victoria and the ACT have the highest population densities in the country, 23.87 and 137.53 people p/sq km respectively. At least in Australia, the denser the population, the less they’re using Facebook.

So, should you buy shares? That’s entirely up to you. But you might want to consider the growth opportunities on one hand with a population chart in the other.

Experian Hitwise. Now you know.