Startups like Podtrac and Podshow Network say they are having success pitching advertisers to spend dollars in podcasts. But neither has announced a multi-million dollar deal, yet. And probably won't for some time.

Will program producers have patience, or will their podcasts fade away?

"It's going to take at least 12 months for us to get past the 'test' phase," said Mark McCrery, co-founder of Washington, DC-based Podtrac. With experience that includes a stint at Grey Advertising, McCrery said his firm has been writing podcast sponsor business for a number of podcasts in the range of $10,000 to $30,000.

"Some ad agencies have media budgets for testing," he explained. But it's going to take time for experimental results to produce big orders. "They need to have a good experience." McCrery says the planning and budgeting process inside companies and agencies can take 1 to 2 years. So, it's possible podcast ad marketers may run a test, get good results, and then be told to come back in 9 months.

"I think a year is when we will see significant ad budgets coming into podcasting, resulting in about 50% to 75% of ad inventory sold across a majority of podcasts," McCrery added