The news: Podcast advertising is turning more programmatic, and buyers and platforms are falling into ad-overload habits that have long plagued programmatic display, executives warned at the IAB Podcast Upfront and the Sounds Profitable Business Summit, per AdExchanger.

Podscribe’s Cam Weber cautioned that impression-based programmatic buys can expose a listener to more than 15 ads over a campaign, versus roughly one ad per episode in direct-sold deals.

Zooming out: Programmatic buying is scaling quickly across a growing audio ad market. Amazon’s demand-side platform (DSP) added podcast inventory from SiriusXM, Spotify, Acast, and iHeartRadio earlier this year, and podcast agency Oxford Road said advertisers increasingly run a 70/30 mix of host-read and programmatic ads.

• The share of agencies buying audio programmatically grew 82% this year, per a survey of more than 300 agencies from Advertiser Perceptions and Cumulus Media/Westwood One.
• We expect US programmatic podcast ad spending will reach $462.2 million in 2027—nearly double 2024’s $232.6 million—and will represent 15.6% of total programmatic digital audio services ad spending.

Why this matters: US media consumers find podcast ads less disruptive than other digital formats, but that tolerance could shrink if ad loads become disruptive.

• Only 25% of US media consumers call podcast ads annoying, compared with 50% for online display ads, 46% for YouTube and other video platform ads, and 42% for TV or streaming ads, per YouGov.
• About half of US media consumers have taken action after hearing a podcast ad, including visiting a brand’s site, searching online for a brand or product, or talking to someone about it.

Tolerance and trust could be at risk if ad loads climb. Podcasting’s trust advantage leaves a slimmer margin for error than traditional radio, where ad loads crept up for years with few consequences because listeners could only vote by changing the station.

Implications for advertisers: Overwhelming listeners with ads carries risk beyond the advertiser’s brand equity. Podcasts and platforms that let ad loads climb too high could face their own backlash through listener attrition or lower ad retention.

Advertisers chasing programmatic’s expanded reach without managing frequency risk trading a high-trust environment for the ad fatigue that has already hurt display and video.

Use programmatic ads to supplement host-read ads at the episode and show level, preserving the trust advantage of host-read formats while extending reach into mid- and long-tail inventory.

In addition, podcast backlogs still have life as new listeners discover long-running shows, so older episodes can absorb new ads without adding to the load on current releases. Advertisers running impression-based, cross-episode campaigns should set firm frequency caps and monitor ad retention data to confirm ads are being heard.