How do ad networks differ from exchanges?
Networks are different from exchanges in that they buy inventory, add value in the form of data, technology, and optimization, and then sell that inventory to advertisers. Exchanges simply facilitate the sale of an impression between a publisher and an advertiser.
Exchanges in today's ecosystem lack mature optimization technology and unique or scalable data. And because an exchange simply facilitates a transaction, advertisers don't have certain buying advantages that they can get from buying through a network such as bulk rates, risk-free CPA/CPC, etc.
What is the effect of duplication on a plan?
Duplication means wasteful ad dollars that provide no incremental ROI. It can limit overall delivery and can cause you to pay more for what you could essentially get for less. That said, it is important to recognize how duplication manifests itself in order to plan for it. There is more to duplication than inventory alone -- it transcends the users you reach, and when or how you reach them.
Imagine the multiple non-reserve partners you have on a plan going after the same conversion, as multiple people, showing up at the same place, hunting for the same 10 ducks. They are each equally likely to see the same 10 ducks, but they are unlikely to see each other, or see who is shooting which ducks. Collectively, they end up wasting a lot of ammo (money and impressions) as each individual tries to shoot all of the ducks. If you were to arm just one of these partners -- preferably the one with the best optimization engine, targeting system, data, or inventory access -- and send them out, you would eliminate wasted ammunition and money, achieving the same results. Most importantly, you'd increase your ROI.
Display advertising is obviously more complex (and less violent) than duck hunting -- but the example of multiple hunters on a single hunt defines how many of us buy every day. Duplication is something we need to understand and solve through consolidation.
Access to comprehensive, high-quality, non-reserve, and RTB inventory and audiences at scale are attributes of a partner that can solve for duplication through consolidation. Access to exchanges and RTB inventory alone is not a differentiating factor -- they are publicly accessible to all with technology. Having a publisher services team and maintained relationships with a network of sites, allows access to inventory and audiences that would not be reached through exchanges. There are a lot of different factors that go into duplication. It is important to test, control for those factors, pinpoint wasteful media, and remove that duplication.