Ecotality is basically admitting that it doesn't know how much to charge for an EV fast charge. That's why the maker of Blink EV charging stations just started testing pricing models, posting on its blog that it would change pricing plans for US markets "on a regular basis." Ecotality will collect the data, measure usage and use that info to figure out the theoretical pricing sweet spot. It's a tough decision, because you can charge for the juice in any number of ways.
Judging the initial response to a plan to charge $5 per charging event for subscribers ($8 for "guests") things are a bit sour. That's the rate now in effect in California (so, Los Angeles, San Diego and San Francisco). No one there seems real happy with the one-size-fits-all flat fee and many say that either a per-second or per-kilowatt fee would be more equitable. Ecotality wants data from more markets to calculate the price, and says it will start enacting pricing plans in Arizona, Tennessee, New Jersey and Pennsylvania to find the elusive right revenue model. To which we say, good luck. Check out the company's blog post (and comments) here and note that the company does say, "We will collect the data on usage and then identify the model that works best."