I’ve always loved the notion of programmatic RTB. As a data hound and an early adopter of Appnexus , the notion that advertisers can achieve highly granular levels of targeting and utilize algorithms to impact performance is right in my wheelhouse. Today’s ad tech, replete with 300 companies that enable data-driven audience segmentation, targeting, and analytics is testament to the efficiency of buying ads one impression at a time.

But what if driving efficiency in display actually does more harm than good?

Today’s RTB practitioners have become extremely relentless in pursuit of the perfect audience. It starts with retargeting, which uses first party data to serve ads only to people who are already deeply within the customer funnel. No waste there. The next tactic is to target behavioral “intenders” who, according to their cookies, have done everything BUT purchase something. Guess what? If I have searched 4 times in the last three hours for a flight from JFK to SFO, eventually you will get last view attribution for my ticket purchase if you serve me enough ads. Next? Finding “lookalike” audiences that closely resemble past purchasers. Data companies, each of whom sell a variety of segments that can be mixed to create a 35 year-old suburban woman, do a great job of delivering audiences with a predilection to purchase.

But what if we are serving ads to people that are already going to buy? Is efficiency really driving new sales, or are we just helping marketers save money on marketing?

It seems like online display wants to be more and more like television. Television is simple to buy, it works, and it drives tons of top funnel awareness that leads to bottom funnel results. We know branding works, and even those who didn’t necessarily believe in online branding need look no further than Facebook for proof. With their Datalogix offline data partnership, Facebook conclusively proved that people exposed to lots of Facebook ads tended to grab more items off of store shelves. It just makes sense. So why are we frequency capping audiences at 3—or even 10? I can’t remember the last time I watched network television and didn’t see the same car ad about 20 times.

The other thing that RTB misses out on is profit. RTB drives advertising towards lowering the overall cost of media needed to drive a sale. Even if today’s attribution models were capable of taking into account all of the top-funnel activity that eventually creates an online shopping cart purchase (a ludicrous notion), we are still just measuring those things that are measureable. TV ads, billboard ads, and word of mouth never get online credit—yet I believe they drive most of the online sales. Sorry, but I believe the RTB industry creates attribution models that favor RTB buying. Shocking, I know.

So, what is true performance and what really drives it? For most businesses, performance is more profit. In other words, the notion that a sales territory that has 100 sales a day can generate 120 sales a day. That’s called profit optimization. If I can use advertising to create those additional 20 sales, and still make a profit after expenses, than that’s a winner. RTB makes it cheaper to get the 100 sales you already have, but doesn’t necessarily get the next twenty. Getting the next batch of customers requires spending more on media, and driving more top-funnel activity.

The other thing RTB tends to fumble is how real life sales actually happen. Sure, audience buying knows what type of audience tends to buy, and where to find them online, but misses with frequency capping and a lack of contextual relevance. Let me explain. In real life, people live in neighborhoods. The houses in those neighborhoods are roughly the same price, the kids go to the same school district, the people have similar jobs, and their kids do similar activities and play the same sports. The Smiths drive similar cars to the Joneses, they eat at the same restaurants, and shop at the same stores. If the Smiths get a new BMW, then it’s likely the Joneses will keep up with a new Audi or Lexus in the near future. When neighbors get together, they ask each other what they did on February Break, and they get their vacation ideas from each other. That’s how life works.

What media most closely supports this real-life model, where we are influenced most by our neighbors?  Is it serving the Jones family a few carefully selected banners on cheap exchange inventory, which is highly targeted and cost effective? Or is it jamming the Smiths and Joneses with top-funnel brand impressions across the web? The latter not only gets Smith, the BMW owner, to keep his car top-of-mind and be more likely to recommend it—but also predisposes Jones to regard his neighbor’s vehicle in a more desirable light. That takes a lot of impressions of various types of media. You can’t do that and remain efficient. The thing is—you can do that and create incremental profit.

Isn’t that what marketers really want?

[This post originally appeared in AdExchanger]