I just searched "Firefox" in the app store. The top result is Google Chrome with an Ad indicator (Google paid for higher placement). Second is Firefox.
Sometimes it's good to live in a region that no one cares about. I just searched for Firefox in the Android Play Store application, there were no ads, and the first result was Firefox.
I also don't get any ads in American and UK podcasts for the same reason (except for those read by the host, but there are few of those and they're easy to ignore).
On iOS App Store at least, my observation is they just show you a random irrelevant ad at the top if there’s no one specifically bidding for the term. Well that’s my assumption for why I get irrelevant <app with deep pocket> ads when I search for obscure terms. But maybe they don’t show an ad if there’s no bidder at all for garbage spots in <country>?
Podcasts are normally plain mp3 (or similar) files that get downloaded as-is off an rss feed, as far as I understand. I don’t think anyone gets extra ads outside the sponsored/host-read ones.
The big podcast networks like iHeart are able to dynamically splice ads into episodes, so they can be targeted based on geoIP or whatever other signals they have on you.
Everyone posts to centralized RSS feeds these days. The company that owns the feed creates duplicates of the uploaded file, inserts ads into them, and serves a version of the file containing ads localized to the downloader's country.
If the same podcast is uploaded to Youtube through the uploader's official channel, it won't contain those ads and you're better off downloading that.
