Malcolm Wall, chief executive of Virgin Media's Content Division, said testing is currently underway for pre-, mid- and post-roll ads to be placed in VoD content.
However, he said that other advertising models are more likely to "see the light of day" first, such as the carrying of targeted advertising around sections of the EPG.
For example, advertising for travel companies could be placed around the lifestyle section of the cable operator's EPG.
He said: "My view on monetising VoD is that we can do inserted ads around VoD on a pre-roll or post-roll basis. I think we will probably do that.
"But we are not ready to do that just yet. If we did it now we would have to sell (the inventory) quite cheaply and we might not get the right price when the medium becomes more widespread."
Wall noted that Virgin plans to continue testing VoD advertising to build a "body of research" that will enable it to sell the inventory more effectively to advertisers.
He said: "There is an issue of measurement. TV is very measured, but for VoD it isn't there right now."
VoD will remain the focus for much of Virgin Media's strategic efforts in the coming months, with Wall revealing an upcoming expansion of the service, led by the addition of more than 2,000 hours of additional content.
The company is in talks with the BBC about launching a TV set-based version of the corporation's VoD service iPlayer.
"Our real focus is enhancing VoD," Wall said. "We currently have 3,700 hours and we need to grow that. We want to get that to 5,000 hours by early 2008.
"We want to strengthen in areas such as entertainment and children's and are looking at the long tail like ethnic film and education."
Meanwhile, Virgin Media will launch round-the-clock high- definition TV linear channels for the first time next year.
Currently, it offers HD content through its VoD service, including around 50 hours of HD movies. The BBC's linear HD channel is carried by Virgin, although that channel airs content for a limited number of hours per day.
Wall added: "We are bandwidth constrained. We have enhanced head ends for HD channels. But the main focus with HD is VoD and it's our belief there is an appetite for HD film. However, we hope to add HD channels on a selective basis."