Wow, solid post, and a good warning. I have some friends who have gone heavily, heavily down this road - particularly with MMOs. Literally seen it end relationships...
It's not only the competitive element that gets people going - the social side of things, plus the pure escapism are very powerful draws to these online worlds.
A former housemate of mine would get home and play for about 6 or 7 hours before going to bed around 1 or 2am, go to work on only 4 hours sleep, then on Fridays he'd be online from the moment he could right through until 2am on the Sunday again, only the shortest of eating, sleeping and "bio-breaks" seeing him away from the PC.
He was late for a New Years' Eve party with his girlfriend because of MMOs, and that relationship came to an end not long after.
The sad tale does have a happier ending, though, as he met his now wife and mother of his children while playing... I think it was Star Wars: The Old Republic... and they have a much more balanced and 'normal' lifestyle now, making time for MMOs, rather than making time for each other.
A great cautionary tale, @renzoarg - I hope this makes it into trending as a lot of people could do well to learn how easily one can get sucked in!
@badastroza this is a wonderful, well thought out comment! I gave you a little boost in hopes you get more recognition. :)
Well thank you very much! Appreciate that.