Once upon a time, digital advertisers had to approach publishers directly to place their ads on websites. It wasn’t cost-effective, and it definitely wasn’t a very scalable way to operate, as marketers had to piece together each advertising campaign by individually contracting with hundreds of individual websites and publishers. However, on the up side, it gave advertisers control over where their ads were being placed. Then, ad networks emerged as middlemen, offering a way to reach audiences across many publishers. But, ad networks are not necessarily transparent about their fees, margins, and inventory, and they lack efficient controls (like frequency-capping or budget-management) across multiple exchanges. Now, over the last few years, the programmatic — or automated — purchase of display ads has been on the rise. This year alone, more...