Today there was an enquiry running on the radio about Facebook addiction. Apparently lots of people can't bear to be away from FB, and would do anything to be on it - neglect their work, their family, their tasks at home.
The hosts of this popular Radio 2 program 'De Madammen' (= the ladies) dared a listener to enter their competiton to do one whole week without FB.
They interviewed several listeners, who all confessed to being active on FB for a great deal of the day.
Now I must confess I like to go to FB as well, because I like to play some games on it like Written in the Sand. Quite an addictive game, as you have 2 minutes and 30 seconds to form 12 or more words with letters given. I play it together with my sister, and our best result is finding those words with a time left of 2 minutes 12 seconds! So now we try to improve our best and play several games a day, after work.
So yes, FB is addictive in that sense. Before Facebook existed, we did other games, like scrabble or card games. Times change, eh?