How are ads inserted into my podcast feed?

recently some podcast episodes like tonight’s TWIET have run into some difficulty when I try to play from apple podcast app through my router. the only evidence I see when snooping is a dns request for chtbl dot com comes back with so I suspect it is being blocked by DNSBL as advertising. am I on the right track here? so much for saving cellular data…

Yes, TWIT uses chtbl and megaphone to insert ads into podcasts that have “open” advertising slots - i.e. they didn’t get native advertising.

I had to whitelist them to be able to download the TWIT podcasts.

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One presumes that complete single files are still being served. The difference is that instead of getting the single file direct from TWiT, with native ads, direct from TWiT’s CDN, you’re now getting something generated for you (potentially on the fly) from the Megaphone or Chartable servers with ad insertions from a third party. I don’t believe this is dynamic in that it’s downloading the ads at time of insertion, as a webpage would, or even as YouTube would, because podcasts were always about a single file/stream per episode.

I don’t understand this statement. If you didn’t block the provider, you would be downloading a single episode, just like always. It doesn’t affect you data consumption who provides the episode to you. Additionally, as the 3rd party ads are likely significantly shorter than a native ad read (30 seconds versus 3 minutes or more) I don’t think you can complain about the 3rd party ads taking more data. (Given that the idea is the ads are necessary for the functioning of TWiT.)

I don’t want to globally unblock an advertiser so when an episode is thus tainted I download via cellular. hence data usage.

it is bad enough to have 5-minute long ads in a podcast let alone one that is not controlled by twit - some of them are rather odd. fortunately my podcast player has a button that helps skip over them. this is a win-win because twit gets money and I minimize the annoyance of hearing the same ads over and over. Even a one-off ad is still a duplicate as I listen to my favorite shows twice, both live and thru the cast. can’t skip over them while live so to be sure I have heard them.


It’s not like they’re generically advertising anywhere else, they’re a podcast ad insertion provider. Since you don’t get to decide which podcasters use Megaphone… if you want the content, and it is served via Megaphone, then you’re going to have to unblock them or go without the content.

I would need to go hunting, but @Leo has posted a couple of times the domains to be whitelisted for successful podcast listening.

Chartable is for analytics.

When we host shows via Megaphone (and nearly all our audio shows are now hosted there) you’re getting the show directly from Megaphone (instead of Cachefly). Megaphone might insert ads based on your IP address. They’re burned-in - part of the entire download.

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interesting. so it seems if apple podcast app can’t do the analytics it will not serve the episode. nice

Apple for sure doesn’t block Megaphone. Many many podcasts use it, including, the NY Times.

when apple podcast player can’t get the IP of chartable it will not pull down the podcast. so I have to turn off my wifi to get the episode. (courtesy of wireshark)

Yes, this is correct. Chartable is a proxy. They allow you to track how many people download the podcast episode, so they can reveal info about popularity, and how people are finding the podcast, etc. Basically they’re helping a podcaster know what’s working and what doesn’t work, and it allows them to have numbers for advertisers (presumably the ones buying the native (host read) ads, because Megaphone provides its own means of tracking.) So you request something like and they mark the attribution and forward your download onto the CDN (so maybe Megaphone in the case of TWiT.)

The goal is to allow podcasters to show the number of downloads, and possibly where those downloads originate from (by country and state say.) It’s certainly not tracking anyone beyond that because it’s not really possible.

Once you successfully locally download the episode, it’s up to you and your podcast/playback app where, when and how you listen. It could be possible that the podcast app is also tracking you, and in the case of Apple that’s almost certainly to be the case, because they want further info for their recommendations and popularity charts.

Please remember that TWiT is an ad sponsored network. If it weren’t for the ads (either the live reads by the hosts or the ones Megaphone inserts) there would be no network. The analytics are necessary in order to attract ad purchasers. If anything, the ad purchasers want more information than is collected.


no trouble remembering that - twit has the longest in-content ads of any podcasts I subscribe to. I choose not to give chartable blanket approval on my router and will switch to cellular when I must. but then I know it is happening.

spoke too soon. two issues of ttg and the big twit announcement episode got blocked by pfsense etc. trying to nudge us toward a membership?

There is no conspiracy here. If you use block lists with your networking, those block lists are maintained by people not associated with TWiT and contain entries that may affect your ability to use services that TWiT uses to deliver its content. If you’re having problems with block lists, you’re going to have to work them out with the block list providers, or make manual edits/bypasses.


Nothing has changed.

Like many podcasts we redirect through several services for download measurements and ad tracking. It looks like one of these services has been added to your ad blocker list.

To continue freely downloading our shows, you’ll need to whitelist the following URLs in your ad blocker: (TWiT) (Chartable) (Podsights) (Megaphone)

Sorry for the bother. This is something we have to do for our survival as a free podcast - the good news is that neither we nor these services are doing anything other than recording your IP address. They are fully GDPR and California Privacy Act compliant.

The Club TWiT versions do not have these redirects, but, unfortunately, is what’s required these days to sell advertising. It’s one of the reasons we started Club TWiT - we don’t want to track you any more than you want to be tracked.


perhaps someone could explain why these sites (excluding have earned a reputation enough to be blocked by steve’s favorite firewall.

Their main purpose is to track users of other websites.

While megaphone, for example streams podcasts and inserts adverts, it also collects information about the user for the advertisers.

Like it or not, in order for TWiT to get advertisers, they need to use these services to get metrics to provide to the advertisers. In this day and age, no one is going to advertise without knowing how useful the campaign is. Leo has previously stated that if he had a choice, he would not use these services. In response to this, Club TWiT was released last week where for a low monthly subscription, you can get podcasts direct from TWiT without the tracking, and without the ads.