In the old days, like back in 2007, birthdays came and went with little online fanfare. Sure, you got phone calls and voice mails that needed to be returned. You might even have gotten some email birthday wishes that needed to be replied to. But the main celebration revolved around real life friends and getting together.
Today, and in fact, it really is today for me, you must monitor your large social networks for birthday wishes. I am connected with many more people online than I would see in person on my birthday. In my case it started with Facebook messages yesterday, and continuing with many more today. I also received messages on Twitter from friends and bots. And it is my responsibility to keep up with the messages all day long and thank each and every person for their wishes. They are truly appreciated.