Vendors of IP PBXs point to rapid returns on investment at companies with at least five locations and 2000 people. Small organizations, under 100 phone extensions, may not see such a good return on investment:
Smaller companies, particularly single-site businesses, show different economics. An online ROI calculator for SIP trunking (www.fliptosip.com) presents a selection of company sizes that starts with “5 to 3000” employees—a hint that very small companies may not be good candidates.
Startups with no previous investment are best situated for VoIP. They can build once for both voice and data (and video) services while ensuring sufficient capacity. There is no capital investment to write off nor any need to pay for removal of old equipment. And since new telephone equipment is almost all based on VoIP, this kind of firm's most attractive other choice could be a refurbished digital PBX.