Projection Rejection

A Company of Friends member emailed other members of his group earlier this week with the following question:

Yesterday, I had a discussion with a client, an SVP of product management, who — along with all present — agreed that what I had proposed was a real, qualitative breakthrough. The SVP then asked for quantitative support, saying “We need some numbers, projections of how successful we will be using this breakthrough approach.” How can “projections” of data describing current circumstances be faithful (i.e. not be totally made up) and provide any insight into results of a radical conceptual — and operational — change?

Any ideas or insights?