Linkedin, when used correctly, can be an extension of your website, providing information you won't include there, and, contrary to popular belief, it can be customised considerably; giving it your personal touch. You'll notice I said it's an extension of your website, not an extension of your CV. After all, your Linkedin profile can have, among other things:
Valentine's Day started, of course, to commemorate the occasion in 346AD when a valentine was crucified on a heart-shaped Thorntons milk tray. Ever since in the lead up to Valentine's Day people desperately seek a date to prove they're not fundamentally unloveable, these days often using dating apps like Tinder, OK Cupid and LinkedIn.
It is fair to say that Facebook has revolutionised social interactions for most people. Whilst, once, friends would call each other on their parents' landline during the evening to catch up, now they are constantly connected in a network where information, news and events enrich and improve the lives of all members.