How do ITSP's sell SIP Trunks? As PRI replacements. As a cost savings against a PRI. It isn't much of a savings and, as I look at it, it seems like the carrier loses revenue and margin (and in some cases customers because SIP is NOT TDM).
If the business owner still has owes money on his PBX or even recently paid it off, getting him to bite on a SIP Trunk will be hard. He needs an IP Card; a service call; and probably a new maintenance contract.
As in this blog post, the IT guy wants more than just a PRI replacement.
"What I really want from SIP trunking is the ability to have and use the same Telco features that I have and use today. The basic features I must have are 3-way calling and call transfer but was told, "Your PBX can do this." Sure, and tie up two CO lines or SIP trunks in the process, how inefficient! Don't offer me advanced features without first meeting my basic telephony needs because my customers don't really want to give up what already works as a sacrifice to get those "advanced features." Is SIP trunking feature rich? It depends upon the provider and your gear and the knowledge of the support on both sides, including that of the factory guys."
If you are a Broadsoft shop, you can offer SIP services overlaying on the trunk, so that customers get the benefit of the softswitch. Now you will have to adjust your sales process to make sales. That's right. You will need to have a list of very open questions that the prospect can answer about the LAN, the phone usage, the PBX, and the business process of handling calls. And you need to know your product or take along an engineer. You have 2 ears and one mouth; keep that ratio - listen twice as much as you talk. And I mean actively listen. You won't be able to provide a solution without hearing everything. It's not like a PRI, where there are only 2 configurations and how many B channels.
One example is in this article: "Teoma Systems responded to these challenges by changing its sales process to a team approach, which typically comprises four people: a salesperson, an engineer, a technician, and the CFO. Each person is a subject matter expert (SME) who can present Teoma Systems’ value proposition from a different angle."
The easiest way to sell SIP trunks is to just replace PRI's, but by adding SIP benefits to the basic features of dial-tone, you can create added value, which means either more money or stickiness.