DSPs, Ad Networks, and Everything In Between: What Advertisers Really Need to Know Now

Originally published in 2018, this post was updated in October 2025 to reflect current programmatic buying trends.

Programmatic media buying has become a connected network of advertisers, publishers, data providers, and technology platforms. Each plays a role in how digital ads are bought, sold, and optimized across channels. Yet even with all that innovation, one question still lingers: what’s the difference between a DSP and an ad network?

Let’s clarify what each does, how they’ve evolved, and why it matters to advertisers today.

What Is a DSP?

A Demand-Side Platform (DSP) is the technology advertisers use to buy digital ad inventory programmatically. It acts as the buyer’s access point to multiple ad exchanges and supply-side platforms (SSPs) through one interface.

Instead of manually purchasing placements from individual publishers, DSPs use automation and data to decide where and when to serve ads in real time. This allows advertisers to reach specific audiences more efficiently and measure performance with greater accuracy.

In today’s landscape, DSPs:

• Access inventory across multiple formats, including video, audio, digital out-of-home, and retail media.
• Use first-party data, contextual signals, and modeled insights rather than relying on third-party cookies.
• Integrate with measurement and clean room partners for privacy-safe reporting.
• Apply AI-driven optimization, helping campaigns improve performance automatically.

What Is an Ad Network?

Before programmatic technology became standard, ad networks acted as intermediaries between advertisers and publishers. They collected available ad inventory from multiple sites, packaged it into segments (such as by audience or vertical), and sold it to advertisers at a set price.

While ad networks still exist, they now play a smaller and more specialized role. Some focus on niche verticals or formats, while others operate as managed service partners within broader programmatic ecosystems.

In short:

• Ad networks provide curated inventory packages with fixed pricing and limited transparency.
• DSPs offer real-time access to global inventory with flexible bidding and data-driven targeting.

Traditional ad networks helped scale digital advertising in its early days, but they lack the control, transparency, and adaptability that modern advertisers expect.

How Programmatic Buying Works Today

Programmatic buying has evolved far beyond the basic buyer–seller exchange. Advertisers now use DSPs to connect with:

• SSPs (Supply-Side Platforms) that represent the publisher’s side of the exchange.
• Data providers that enhance targeting through audience or contextual insights.
• Measurement partners that validate performance across channels.
• Retail media networks that give brands access to high-intent audiences within e-commerce environments.

According to Statista, global programmatic ad spend is projected to surpass $725 billion by 2026, representing more than 90% of all digital display advertising. That growth reflects how central programmatic buying has become to modern marketing strategies.

Why Multi-DSP Strategies Matter

No single DSP offers full coverage of all inventory, data, and formats. Each platform has its strengths, whether it’s unique access to streaming TV, proprietary audience data, or regional inventory. Relying on just one can limit reach and create performance risks.

eMarketer reports that nearly 70% of large advertisers now operate across multiple DSPs to diversify access and maintain control over pricing and data ownership.

Working with a partner like Digilant gives advertisers visibility across platforms, data partners, and channels. By connecting multiple DSPs, we help brands compare performance, measure results consistently, and make smarter optimization decisions.

What This Means for Advertisers

The difference between a DSP and an ad network is more than a technical distinction. It represents the shift from manual media buying to intelligent automation and data-driven decision making.

Advertisers today need partners who can navigate that complexity, connect the right technologies, and deliver results across a fragmented ecosystem.

Digilant helps advertisers do exactly that—turning technology connections into measurable performance. Contact us today to get started!