Prince William knows this: several times, over the past few years, Britain's tabloids have got all a-tizz about Facebook sites on which his friends Archie and Charlie and Alexandra Harrumph-Hurrah have discussed plans for the weekend's polo and parties.
All the moresurprising, then, that the heir to the throne has decided for the first time to post what he's up to on Facebook and Bebo.
It will be a short trial: three days of status updates from his official trip to Auckland and Wellington next month.
But if it is successful, who knows?
This week, after all, British government documents revealed plans to make the Prince "shadow king", taking up many of the Queen's public duties in coming months. The Royals have even asked for a new tax break to subsidise 27-year-old William's PR office, as he is charged with communicating the monarchy to a new generation.
Surely, there can be no better way to make him relevant to other 20-some- things than by posting over-exposed photos every Saturday morning of what he got up to in Boujis bar in Mayfair the previous night; status updates from dry official engagements reporting how he is recovering from his hangover.
This first trial has got off to a cautious start. Wills had been "utterly captivated" by New Zealanders when he visited in 2005, he wrote. "Since then, New Zealand has become a very special place for me. I hope that you find this new site informative and interesting."
That worthy tone - "informative and interesting" - is not quite what many people seek from Facebook.
The social networking pages were set up at the request of the New Zealand Government and all inquiries are being directed to the Prime Minister's office, no less.
The Visits and Ceremonial Office has hired a contractor with experience in highly-secure sites that the government agency lacks. That contractor is not being named for security reasons, but Prince William's office is signing off all the content before it is uploaded.
Next, we expect to see Wills tweeting his grandmother from state dinners.
