Good point - that's exactly the type of answer I was hoping to get. I guess I forgot the value in being close to the metal. Twilio's customers aren't necessarily end customers but companies who, themselves, are attempting to make serious money from Twilio's products and will be forking over huge amounts of cash on a regular basis ;-)
I doubt many single customers will require multiple thousands of phone numbers or be using more than 15 million minutes a month (that's 1,500 people on the phone for 8 hours every week day of the month).
OpenVBX is somewhat a direct-to-business play, but they stayed out of the pool by open sourcing it and then by hinting that others are allowed to re-sell it (more minutes for them!). It's really slick though:
I could see a Big Telco scoop them up for tons of money in the near future. All those cushy business lines are going away at a rapid pace, they need to get in on the next big thing. The players are huge, a $100 million buyout would barely even make the company newsletter (case in point, AT&T banked $12.5B last year).
