Programmatic pricing's valleys and peaks, like in every other kind of ad sales, are driven by demand and a host of other often unforeseeable factors affecting different audiences and consumer segments.
The general trend, however, is up.
"We've seen a very consistent gradual price increase in the overall price of everything," said Bill Guild, vp of marketing at programmatic marketing company ChoiceStream. "There are more bidders entering the marketplace, also more premium content being placed. More valuable content being put into the marketplace means prices go up."
Guild said ChoiceStream is also seeing more branding campaigns in its exchange. The increased competition could be contributing to price increases, as could the fact that the campaigns buy on a different metric, he said.
Beyond that overall observation, Guild said it can be tricky to draw conclusions from pricing data. For example, in the infographic below, which shows the cost index for January 2013, 2014 and 2015, ads in the home and garden segment swung from well above average to well below; it's not clear why.
Also, he said: "Not every brand tracks the same way. Auto prices tend to exhibit the kind of seasonality you would expect. But then there are whole categories that always seem to be very expensive. Other things may be indicative of industry changes, like security software and navigational systems. They were going well and then the market imploded."
In spite of the difficulty in interpreting price swings, there is a strong demand for programmatic data, as more marketers begin to incorporate it into their media buying.
ChoiceStream has been continually monitoring changes in the cost index for consumer segments, and last year began publishing its findings on a monthly basis to illustrate to advertisers how seasons, holidays and industry trends affected the prices that they paid, on average, for digital advertising.