"What's the RoI model?", as if it's that straightforward. There isn't an RoI model, it's as simple as that. That's not to say there is no point in connecting the stadium - there absolutely is - but approaching the problem in such linear terms is a complete red herring.
There is a reason that the Connected Stadium vision has never got out of square one in Europe. The reason is that the sellers generally don't understand the buyers and the buyers generally have no idea what they're buying. It's time for a more consensual approach: everyone needs some skin in the game.
For too long, the sellers have been trying to wow the buyers with their technical solutions. For too long the buyers have had no marketing strategy of their own so they have no idea how the buyer's product might help move them to where they need to be.
It's high time the sellers stopped selling technology and started selling customer solutions. If the buyers could then utilise those solutions to plug gaps in their strategy then we start to have the makings of an RoI model. Each model will be different, of course.
Of course, that is just the start. Just because customers can get online whilst in your venue doesn't mean you're suddenly going to double sales of your poor quality, overpriced replica shirt (that is another discussion altogether). In the same way that creating a Twitter hashtag campaign doesn't suddenly mean you're "engaging" with your customers, your Connected Stadium is a means to an end, it's not a silver bullet.
We're always looking for short cut, an easy answer to things and like most things that are worth doing, the Connected Stadium model is worth doing properly. Think of it as an alternative to your website: it's a gateway. Beyond that, if your products and services were not selling before, there is probably a reason for it and this new way of selling them isn't going to change that.
The way I see it, the connected experience at entertainment venues by-and-large is behind that of your average coffee shop. The live experience in many people's eyes is lagging way behind the televised experience. Something has got to give: if not for today then what about tomorrow? Google's "Generation C", those interested in creation, curation and community aren't interested in appointment viewing, or sitting on their hands for 90 minutes. The only good thing with not being connected is that they can't immediately share their disappointing experience with their network.
The question is not about cost, it's about value creation. We're all in the entertainment business and your customers are all getting better at judging what constitutes value. Connectivity is viewed as an absolute minimum requirement these days, especially by younger consumers (see the bastardisation of Maslow's Hierarchy of Needs). The RoI model needs to be judged not on how many more hot dogs have been sold but on how many people actually turn up in the first place.
The Connected Stadium isn't the solution - as I say, it's not that straightforward - but it's a vital part of that jigsaw. The question really needs to be "how can I afford not to Connect?".