It doesn't have to. It just needs to help electric cars reach the critical mass needed before companies enter the charging station market.

It's great for early adopters. Eventually, as everybody switches to electric, the advantage will disappear, but by then, everybody has switched to electric, so that's all good.

And by then there will be a market for commercial charging stations, if they are necessary.

The version that scales better is inexpensive pay charging stations.

Ubitricity is an example of such a scheme:

http://youtu.be/rKaEhBjt1ls