Not bandwidth as in backbone, but Bandwidth.com. In this GigaOm article, the $85M in revenues comes from other VoIP Providers like Voxeo, ifbyphone, and, wait for it, Google. BW.com back ends for GOOG-411 and Google Voice.
The CTO thinks that five-nines is going away. Sure. VoIP took off because people were used to a crappy cell phone call quality. So to save money they went with VoIP. But if you are still selling on price then you are missing the boat -- "delivering “productivity as a service” and integrated into unified messaging, video and social networks" is where BW.com thinks the money is. (I agree).
Back to the call quality, in an interview on TMC, Jeffrey Szczepanski, co-founder of Allworx, says, "In fact, even under nominal circumstances using the same G.711 encoding that the PSTN uses, VoIP communications audio quality can actually measure slightly worse (in terms of MOS scores, for example) than the typical straight PSTN call because of the added latencies of the packetized data networks that the audio moves through." BW.com is doing VoIP Peering. Broadsoft clients are working on HD Voice Peering. The VPF has been peering for years. It still means that you have costs - connection to the peering point for example - and it means you have packet latency, but it means that you can reduce the amount of analog-digital conversions which will improve call quality.
An excellent article: Wired for sound: how SIP won the VoIP protocol wars
Hosted Phone Systems Offer Most Benefit is an article for your sales team to read.