I'm not the person you're asking, but most websites offload the ads to a different service on a different server. It's the difference between your favorite podcast performer reading some copy, and a movie on TV fading out to showcase the great deals at Luke's Honda Dealership & Taco Shop Come On Down For The Tastiest Deals In Town.

It also strongly indicates that the podcast author has vetted the ads, and is at least implicitly approving of the product; on the web, it's very likely that the author has absolutely no idea what ads are being shown to their visitors.