MailAdx vs Passendo for newsletter ad serving
Passendo is an email ad network focused on programmatic demand. MailAdx is publisher-owned ad infrastructure with SSP, DSP, and open-time serving.
Passendo operates as an email advertising network that connects publishers with programmatic demand. Publishers integrate Passendo's tag and receive ads from Passendo's demand pool. The model is similar to other email demand networks: fast setup, network-managed advertiser relationships, and revenue share economics.
MailAdx is infrastructure you control: an SSP for inventory management, a DSP for advertiser campaigns, and an open-time ad server that runs the waterfall when subscribers open your email. You set floor prices, approve advertisers, and connect to demand sources you choose — Passendo included via OpenRTB if desired.
The choice depends on whether you want to join a demand network (Passendo) or own your ad stack (MailAdx). Many publishers start with network demand and graduate to owned infrastructure as their newsletter revenue grows.
Passendo is headquartered in Europe and has historically focused on the Scandinavian and wider European publisher market. Its demand pool reflects that geographic concentration — strong for European newsletter audiences, thinner for US-focused newsletters where most programmatic ad spend originates. MailAdx's OpenRTB integration connects to global programmatic demand without geographic restrictions, and US-focused publishers typically see more competitive CPMs because they're closer to where the largest programmatic budgets are concentrated.
The practical cost comparison: Passendo charges a revenue share on network demand. MailAdx charges a flat serving fee per impression. At $2,000/month in gross ad revenue, Passendo's cut (assuming 30%) is $600. MailAdx's serving fee on the same impression volume (assuming 40% open rate on 100,000-subscriber send, 3 sends/month) is roughly $48–$72 per month. The serving cost is meaningfully lower once you have the direct or programmatic demand to fill your inventory.
The caveat is that MailAdx's economics assume you have demand flowing through the system — either direct deals you've sold or programmatic fill from MailAdx's DSP and OpenRTB sources. Passendo's network provides demand out of the box. For publishers without existing advertiser relationships, Passendo's demand can be valuable even accounting for the revenue share, particularly in the first 6–12 months before a direct sales motion is established.
Feature comparison
| Feature | MailAdx | Passendo |
|---|---|---|
| Publisher-owned ad stack | ||
| Open-time ad server | ||
| Custom floor CPM management | ||
| Direct-sold deal management | ||
| Advertiser self-serve DSP | ||
| Instant network demand | ||
| No revenue share | ||
| OpenRTB integration | ||
| Works with any ESP | ||
| Multi-publisher network portal | ||
| Native ad format (composite PNG) | ||
| Ad Journeys (sequential campaigns) | ||
| White-label publisher portal | ||
| Self-serve onboarding |
Where MailAdx wins
Infrastructure vs network membership
Passendo is a demand network you join — they fill your inventory from their advertiser pool on their terms. MailAdx is infrastructure you own: configure floors, manage direct deals, and connect programmatic demand on your schedule. When you outgrow passive network monetisation, MailAdx scales with you.
Transparent economics
MailAdx charges a flat per-impression serving fee. Publishers keep 100% of advertiser spend above that fee. Network models like Passendo typically take a revenue share, which reduces publisher yield and limits pricing control.
Direct advertiser relationships
MailAdx includes an advertiser-facing DSP where brands can discover your newsletter and run campaigns directly. With Passendo, all demand flows through the network — you never build direct relationships with the brands advertising to your audience.
Multi-ESP portability
MailAdx works with 18 ESPs via the same ad tag pattern. If you migrate from Mailchimp to Beehiiv or add a second newsletter on a different platform, your ad stack moves with you. Network integrations are often tied to specific ESP partnerships.
When Passendo is the better choice
- You want instant access to programmatic email demand with zero sales effort or ad ops setup.
- Your newsletter is early-stage and the overhead of running an ad stack outweighs higher eCPM potential.
- You prefer a revenue-share model with no prepaid credits — you only earn when the network fills inventory.
- You have no interest in managing direct advertiser relationships or setting custom pricing.
Not sure which fits your situation? Talk to us — we'll give you an honest recommendation.
Frequently asked questions
Is Passendo an ad server or a demand network?
Passendo operates primarily as an email advertising network that provides programmatic demand to publishers. MailAdx is a full ad infrastructure platform — SSP, DSP, and open-time ad server — that publishers own and configure.
Can I use both Passendo and MailAdx?
Yes. MailAdx supports OpenRTB demand sources, so Passendo or similar networks can be connected as a waterfall tier alongside your direct-sold deals and other programmatic sources.
Which platform gives publishers more revenue control?
MailAdx gives publishers full control over floor CPMs, advertiser approval, category blocks, and direct deal pricing. Network platforms like Passendo set terms and take a revenue share, limiting publisher optimisation.
Does Passendo work outside of Scandinavia?
Passendo's demand pool is strongest in Scandinavia and Western Europe. US-focused newsletters typically see thinner programmatic fill and lower CPMs from European-focused demand networks. MailAdx's OpenRTB integration connects to global programmatic demand without geographic concentration, and US publishers generally see more competitive CPMs because they're serving the market where programmatic ad budgets are largest.
How long does it take to set up MailAdx versus Passendo?
Both platforms can be set up in a few hours. Passendo's setup involves adding their tag to your ESP and configuring a few basic settings. MailAdx setup involves the same ad tag step plus configuring publisher placements, floor CPMs, and any direct-sold campaigns. The additional configuration in MailAdx pays off in yield control — you're not just activating a tag, you're setting up a revenue-optimized ad operation.
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