"Collaboration, mobility and social networking are hot topics for enterprises, but the complexity of unified communications technology is contributing to low adoption rates, according to CompTIA's second annual Unified Communications and Collaboration Market Trends study." [source] The whole idea of technology is to make life easier for users, not more complicated. That's why in tech sales, the benefits and uses are stressed, not the features.
VoIP Supply has put out some guides to help businesses understand and adopt video conferencing. Why do you think Skype, SightSpeed, Vidyo and G+ Hangout are used for video chat or three-way video calling? Easier to use!
Hosted PBX is kind of the same deal as Hosted UC. If their current system isn't broken, why switch?
One reason Cbeyond cut its direct sales staff (and hired new ones) was because old telco sales people sell on price and just replace stuff. Hosted PBX, UC, Video Conferencing and CLOUD are all about new ways of doing business - altering business processes. That is a different type of sale.