Choosing a DSP for an enterprise advertiser usually comes down to operating model first, media capabilities second. Since you mentioned multi-seat access and cross-channel campaigns, I’d evaluate DSPs in these buckets:

1) Org structure and access control

For enterprise teams, the DSP has to fit how you work:

• Multi-seat / multi-account support: Can you separate business units, regions, brands, or agencies cleanly?
• Role-based permissions: Can you control who can view, edit, launch, or approve campaigns?
• Shared vs. isolated billing: Do you need centralized spend visibility with decentralized execution?
• Audit logs / change history: Important for governance and troubleshooting.

If a DSP is awkward here, it becomes painful fast, no matter how strong the targeting is.

2) Cross-channel breadth

Check which channels are actually native and which are bolted on:

• Display
• Video / CTV
• Audio
• Native
• Mobile app / in-app
• Digital out-of-home
• Retail media
• Social extensions, if relevant

Questions to ask:

• Are these channels managed in one UI/workflow?
• Can you coordinate frequency, pacing, and attribution across them?
• Are reporting and optimization truly cross-channel, or is each channel siloed?

3) Data and identity capabilities

Enterprise advertisers usually need to bring their own data:

• Onboarding: CRM, MAIDs, hashed email, offline conversions
• Clean room integrations
• Identity graph quality
• First-party audience activation
• Support for suppression, lookalikes, and sequencing

Also verify whether the DSP supports your privacy/compliance requirements:

• GDPR/CCPA
• Consent management integration
• Data residency needs
• Limitations on data sharing with partners

4) Measurement and attribution

A DSP should not force you into black-box reporting:

• Can it ingest conversion APIs, offline sales, and server-side signals?
• Does it support incrementality testing?
• Can you export logs or raw data for independent analysis?
• How robust are its attribution options:
  • last touch
  • view-through
  • multi-touch
  • modeled conversions

For enterprise, the best DSP is often the one that plays nicely with your analytics stack.

5) Optimization controls

Look for controls that match sophisticated buying:

• Custom bidding / bidding rules
• Frequency caps by audience, channel, or seat
• Dayparting, geo, device, inventory controls
• Brand safety and suitability controls
• Supply path optimization
• Curated/private marketplace access
• Automated budget allocation across lines of business

6) Supply and inventory quality

Cross-channel reach is only useful if supply is good:

• Premium CTV availability
• Transparent publisher access
• Fraud and IVT filtering
• Viewability standards
• SPO and deal management
• Marketplace quality and direct integrations

Ask for proof around:

• reach by channel
• duplication across channels
• cost efficiency vs. open exchange
• deal performance vs. open market

7) Workflow, support, and service model

Enterprise teams need more than software:

• Onboarding and training
• Dedicated account support
• Troubleshooting SLAs
• Managed services options
• Change management for seat setup, migrations, and taxonomy

If you’re running multiple brands or agencies, the best vendor is often the one with strong operational support, not just strong tech.

8) Reporting and enterprise governance

You want reporting that can be sliced by:

• seat
• brand
• region
• channel
• campaign
• audience
• deal ID
• publisher
• creative

And exported into:

• BI tools
• data warehouses
• MMPs
• attribution platforms

Also consider:

• API access
• scheduled reports
• naming conventions and taxonomy enforcement
• permissioned dashboards

9) Commercial model

Don’t just compare media fees:

• Platform fee vs. take rate
• Data fees
• Minimum spend commitments
• Seat fees
• Service fees
• Contract flexibility
• Transparency on pass-through costs

A cheaper DSP can become expensive if it requires extra tools or manual work.

A practical way to decide

Use a scorecard with weighted criteria. For enterprise advertisers, I’d usually weight like this:

• Multi-seat governance and permissions – 20%
• Cross-channel execution – 20%
• Measurement and reporting – 20%
• Data/identity integration – 15%
• Inventory quality and supply transparency – 10%
• Optimization controls – 10%
• Commercials and support – 5%

Then run a pilot:

• 1–2 regions or business units
• 2–3 channels
• one first-party audience use case
• one incrementality or lift test
• one reporting export into your internal stack

Compare on:

• speed to launch
• ease of governance
• media performance
• reporting quality
• internal team adoption

Rule of thumb

• Choose a DSP with strong governance and reporting if you have many seats, brands, or agencies.
• Choose a DSP with strong cross-channel buying and premium supply if CTV/video is central.
• Choose a DSP with best-in-class data activation and measurement if first-party data and incrementality matter most.
• Choose a DSP with best service model if your team is lean or highly distributed.

If you want, I can also give you:

1. a vendor comparison scorecard template, or
2. a shortlist of common enterprise DSPs and how they differ.