kabam was still in its inif a si. kevin is co-founder of kabam.of the leaders in free world -- free to play games as well. how has this market grown so much? >> the market is growing because there are so many people buying smart phones and tablets these days that can enable a really great gaming experience. today there's about 900 million android devices out on the market, there are 600 million ios devices. you have 1.5 billion devices or so that can play a great game experience. that's enabling companies like kabam to develop great content for these devices that really bring that console quality experience into your pocket. >> how many people who download a game for free which you don't earn anything else then go on to pay for premium product, which is where you do earn money? what's sort of the take home? >> it ranges by game. >> is there an average? >> 10 to 20% of people will end up paying for something in a game. >> what does that do for your -- what sort of margins? i'm trying to work out how good the model is here? >> kabam, we're doing ove

has already filed confidentially sec to go public and followed by robeo who makes angry birds and kabam will be watching to see which one of the guys comes next. my money is on king. >> you know, just happens to be in the neighborhood. #worst excuse ever. speaking of ipos, potbelly began trading today on the nasdaq. and promptly more than doubled in the first few hours of trade. for those investors watering at mouth at the prospect of buying this stock, herb greenberg is here and has warnings for you. herb, don't rain on this parade, please. come on. >> well, mandy, you know, i have to tell you, when you take a look at this, it is -- a company that has a great story to tell. you know, rising sales. got profits and pedigree with its -- private equity firm backing it. but when you take a lower look at stuff like you take a same-store sales for the first six months of the year, up 1.2%, compared with 4.8% first six months of last year. so you start looking at that and people say who cares about the same-store sales because this company puts up a bunch of new stores. and that's where this g