Though WebEx was not first to market, they have done an excellent job capturing market share from their competitors with a highly reliable and scalable, real-time web collaboration solution. (It should be noted that the WebEx products have been documented time and time again as the most superior solution by independent research firms like Gartner, IDC, Wainhouse Research, and Frost & Sullivan.)
When you look at why WebEx has been so successful it's because they have been able to develop and execute on a solid strategy and vision that focuses on delivering unique, comprehensive customer-centric solutions. They then support the strategy and vision with the brightest people in the industry, such as, an experienced management team, a world class sales organization, unlimited training resources, 24 x7 technical support team, production services team, and a newly formed Professional Services Group. These "people resources" cannot be overlooked as they are tremendous value-adds to any new corporate customer. (For example, the new PSG Group provides private consultation for customers looking to further maximize their investment of WebEx across every facet of the enterprise, extending into individual business processes. These guys show you how to do it quickly and successfully. What other company has this? None, only WebEx.)
These are things that the competition do not offer and are things that will always set WebEx apart from them. Having the right strategy and vision to develop the right products supported by the brightest people equals long-term success for WebEx and perhaps more important, success for all WebEx customers.