Second Life, that is. I joined the artificial world that is 'SL' a few years ago, eventually buying quite a lot of virtual 'land' and building a beautiful home by a waterfall along with shopping malls, nightclubs and even an office for my 'real life' company, but now I've cashed out.
Why? Because, eventually, it becomes more expensive that 'first life'. A monthly fee for the land rental which wasn't too far off the monthly council tax (UK land tax) and whereas when I'm walking down a real street or across the real Hampstead Heath I don't suddenly disappear in SL the technology doesn't always keep up with the ideal, so sudden loss of connection ('disconnects') or suddenly finding yourself mov-i-n-g a-t a q–a–r–t–e–r speed ('lag') meant that the enjoyment factor, so necessary for any online experience, was slowly disappearing. Going 'in world' became more of a chore than a happy pastime.
So in the last month, as I was approaching my annual account renewal at the end of this month, a started knocking down my buildings and selling off my unreal real estate, transferring the cash generated (called 'linden dollars') into real money in the bank.
Over the three years I met some interesting people and worked in-world with them on various projects. Fun times, yes, but now ultimately unrewarding and a money pit.