An interview with the Geoff Elfman, a VP of DataCert, produced some statistics that show the penetration of invoice review and delivery systems (Met. Corp. Counsel, Vol. 13, Dec. 2005 at 57). Elfman states that his company has “almost 3,000 individual firms and vendors” using its software and “almost 6,000 law firm or vendor to corporate client connections.” Thus, they have an average of about 2 connections per user, although not every recipient is a law department if you heed the careful term “corporate client,” nor is every user a law firm.
Even if a user is a law firm, it may well be that only one or a few clients of that firm have demanded submission of their bills electronically. In other words, one cannot tell from these figures how many law departments are using DataCert, let alone for what proportion of their invoices or fees paid.
Internationally, DataCert services 100 countries and invoices submitted in 25 currencies, so some portion of the law firms do business outside the US.
DataCert appears to me to be the market leader in number of users, so these statistics at least give some anchor points to the proposition that e-billing has become main stream.