Without auditable metrics you're just blowing smoke
The current state of podcasting statistics is analogous to measuring the reach of a billboard by counting the cars that pass it on the freeway. You end up with the number of people who MIGHT have been exposed to your message, but you have no clue as to the influence of the message you're trying to convey. Your advertisers and sponsors have no idea about the ROI they receive for paying you money.
When we started to build our platform, this was one of the HUGE issues we wanted to address. What Google's success with its advertising programs has shown us is that if you can provide real metrics (ROI) about the effectiveness of your advertising platform to your advertisers' bottom line, they'll spend a fortune with you. If you can show advertisers that by spending N dollars advertising on your platform, they'll make 3xN dollars in return, you have an easy sale. If you can't show that, you wander into the area of spending the tangible (cash) to build the intangible (brand).
The only way you'll ever know if a person who downloads your media to their device actually consumes that media is by putting spyware on their device.
Everyone hates spyware.