Just Google web conferencing to see 18 million results. This list of web conferencing is extensive but far from complete. Conferencing is starting to look like the VoIP space -- a bunch of people jumping in to get a piece of the action. Join.me, StartMeeting.com, Freeconference.com, Yuuguu.com, G+ Hangout, skype and so many more in the no cost variety. These no cost providers compete against the big guns like PGi, Intercall, Cisco's Webex, The Conference Group, Citrix's GoToMeeting, and on24.
As an aside: BigMarker.com is a different concept. More like G+ Hangout, BigMarker is about community collaboration.
One thing for agents to think about: IF there are hundreds of providers out there in any sector, then there IS demand for conferencing - video, audio, web. You should try to grab a piece of it.
If you wanted tips on selling conferencing, the TCA had a panel of conferencing channel execs give pointers in October of 2011. TCA members can watch it on-demand from the archives.
In the video conferencing space, it is becoming a buffet - wholesale, white-label, reseller, and retail; hardware and appliances; gateways and translators for interoperability; smartphone apps and softphones; API's; recording; and webcasting. I guess since airline travel is getting more expensive (and more of a PITA), video conferencing use is increasing. Moreover, with companies cutting the workforce for "synergies", the stranded employees have to do more and more (with less and less). Technology has to provide some productivity gains - the holy grail of cloud communications (of which, video conferencing is one component). Add to that the price of entry for video conferencing has dropped significantly. Sure you can buy a $100K telepresence room, but even $500 laptops come with decent webcams. Smartphones even have high resolution cameras that make video conferencing possible (if there is a strong enough 3G/4G connection and you have enough bandwidth left under the cap).
While video conferencing will not replace face-to-face or a live handshake, it definitely has its use during the sales process.