Start with your business model
The right ad server depends on how you make money from ads. A publisher selling its own inventory, an ad network trading other people's inventory, an agency verifying delivery and a retailer launching retail media all need different things. Write down who buys, who sells, which formats and what volume before you look at any vendor.
The ad server checklist
Formats and channels
- Display, mobile in-app, video, CTV, native and performance formats you sell today and plan to sell in two years
- Support for standards such as VAST, VMAP, MRAID and OpenRTB
Demand
- Direct campaigns, header bidding and programmatic demand in one decision
- Private deals and floor price controls
Targeting and data
- Geo, device, audience, contextual, time and frequency targeting
- Where your data is stored and who can use it
Operations
- Roles and permissions, billing and payouts, fraud filtering
- Reporting speed, scheduled reports and an API
- White-label portals if you resell to advertisers or publishers
Cost and control
- Pricing model: per impression, revenue share or one-time license
- Hosting: vendor cloud, your cloud, or your servers
- Ability to customise or access source code
Tip: model your costs at three times today's volume. A platform that's cheap now can become your biggest expense as you grow. The Own vs Rent calculator helps.
Questions to ask every vendor
- How is pricing calculated, and what will it be at three times my current volume?
- Where is my data stored, and can I export all of it at any time?
- Can I white-label the interfaces my customers see?
- Can features be added for my business, and who owns them?
- How do header bidding and programmatic demand compete with direct campaigns?
- What does migration from my current platform involve?
Common mistakes
- Choosing on today's volume only. Per-impression fees scale with you.
- Ignoring data ownership. Your audience data may be your most valuable asset.
- Buying separate tools for each format. Separate systems can't pick the best ad across formats.
- Underestimating migration. Ask for a migration plan before you sign.
Frequently asked questions
What is the most important factor when choosing an ad server?
Fit with your business model: the formats you sell, the demand you use, and whether you need to own the platform and data. Cost at future volumes comes a close second.
Should I choose a self-hosted or a SaaS ad server?
SaaS is quicker to start and needs no infrastructure. Self-hosted gives you control of data and costs and suits growing networks and publishers. Compare both at your expected volume.
How long does it take to switch ad servers?
Anywhere from a few days to a few months, depending on the number of campaigns, integrations and formats. Running both systems in parallel for a short period reduces risk.
Written by the DJAX AdServer team. Updated September 2026.