I have a couple things to say about online poker... it is more addicting than cigarettes, alcohol, weed, coke, and extacy. In my personal experience anyway....
I played pretty much everyday for like 4 years, first under a fake account my 18 year old friend transferred me money into, and the finally once I turned 18, under my own accounts with my own credit card! 18 Is the magic number here in Alberta, and boy did I drink and gamble. I Had some really good winning days ($3000+) and had some pretty bad losing days ($500+)... In the end had over 1,000,000 hands under my belt (1,000,000 averages out to 40 hours a week, 10 tables at a time, for 4 years)
I played mostly tournaments, probably upwards of 100 a week... the total buy ins would easily totally over $200,000... and probably be closer to $500,000.... it was fun... I also dabbled in cash games playing stakes with a big blind as big as your average home game buy in, but found my niche in tournament play. The four years turned into about $40,000 profit, which is pretty terrible considering that is less than a 10% ROI... and only about $10,000 a year... I decided once I turned 21 I was going to head down to the WSOP and take my shot, so I took that 40,000 to Vegas... entered as many WSOP events as I could afford... I ended up busting out of every single tournament but one, it was one of the $2000 NL Holdem Events... I placed 3rd... for over $200,000. It was one of the greatest moments of my life.
I felt lucky and deserving of a hot streak, one you hear about through online forums, guy turns $200,000 into $20,000,000 in two weeks...I had turned the past four years of $10,000 a year into $50,000 a year... so I went to my hotel lobby and asked to extend my booking two weeks, I was going to celebrate! I was young dumb and 21... so I took $50,000 of that $200,000 and sat down at $250/$500 NL HE table. I had a look around me, and noticed a few pros I had seen online sitting down. I made a mental note to avoid playing any big hands against them without being confident it would be profitable.
Long story, turned really short... over the next week I lost $200,000... got really really high and blackout drunk, woke up in a hospital with a $26,000 medical bill, and a $10,000 credit card bill.
Just keep it under control, and unless you have 40 hours a week free time to dedicate to it, and read tons of books, and forums and such, then don't plan to make any money off of it. It's a fun hobby.
I recently self banned myself from Full Tilt, Pokerstars, Party Poker, Titan Poker, Paradise Poker... and the other sites sucked to bad to ever bother with.
That is my intervention.