Tesla, for context, had 443 Superchargers in the US as of November 2017.
To no one's surprise, Zellmer noted that it's "pretty certain" these chargers will cost money. Porsche hasn't sorted out the business model, the exec said, but it's not necessarily locked to a pay-per-charge model. You could have a membership card, for instance, or an all-inclusive package. Dealerships might also offer free charging to reel in customers. In the long run, Porsche is also looking at chargers near the places you'd expect to find Porsches, such as golf courses and hotels. These 'bonus' locations wouldn't need to have fast charging, though.
The charger arrays will be expensive -- Zellmer warned of "six-digit" costs for dealers. Porsche isn't going into this alone, though, as it has three potential partners (ChargePoint, EVgo and VW's Electrify America) in mind for building the non-dealership locations.
This won't necessarily be great news for the automotive world. EV charging is already complicated due to a mix of formats and speeds, and this risks creating a future where your choice of car frequently limits where you top up. Even so, it's hard to deny the allure of a network that virtually eliminates the pain of slow charging -- you may be more likely to ditch your gas-powered 911 or Macan if you know you won't have to wait hours to get a full battery.