Here is a strong article that we came across as part of our work for a new Canadian VoIP firm.

VoIP Goes to Business Class - Bandwidth.com says there’s a big difference between consumer VoIP and business VoIP. May 15, 2006

VoIP startups such as Vonage and Skype have made forays into the business market and both have experienced success, but the services being offered are more suitable for the very low end of the SMB market: the small office home office (SOHO) market. They are consumer services in disguise.

http://www.redherring.com/Article.aspx?a=16865&hed=VoIP+Goes+to+Business+Class

 

More on the difference between consumer and a business class VoIP:

http://www.bandwidth.com/wiki/article/What_is_the_difference_between_a_consumer_VoIP_provider_and_a_business_class_VoIP_provider%3F