Of course, sequential comparisons between quarters don't reflect the seasonality of a lot of advertising and consumer activity. But given the rise of programmatic and RTB, anything that seems to suggest a retreat, even a slim one, during the holiday season compared to a traditionally slower period like Q3 is striking enough.
Elsewhere, Casale ponders whether RTB growth can go from steady to rapid. And even if browser privacy settings do wind up reducing the value of cookie-based impressions, the rise of mobile ad targeting -- which tend to be cookie-less in general -- could produce greater acceleration over time. For now, the flow of dollars into RTB remains pretty unstoppable no matter the pace.
For the most part, during Q3 and Q4, 15 of the top 22 advertising sectors increased the amount of RTB buying. However, just five categories -- Retail, telecom, automotive, financial services and travel -- dominate the market with a collective 77.2% share of the market. In Q1, the the top 5 controlled 68% of the RTB spending pie.
Speaking of dominance, retail marketers made up 35.8% of RTB spenders, making it by far the number one category. Telecom was a distant 12.9%.
In terms of prices, automakers tended to support the highest winning bid prices in Casale's index, which is natural given that car companies and their buyers place an enormous premium on targeting specific audiences, particularly those identified as "auto intenders."
The average price for RTB between Q3 and Q4 went up 24% (from a 100 index in Q3 to 124 in Q4). This increase was related to an increase in the number of bids per impression -- or, "bid density" -- brought on by the holiday shopping season. And it's another reason that more publishers are finding RTB a bit more attractive these days. But between the browsers' war on cookies and dominance of the market by a few categories, the report shows that RTB's rise is not exactly a straight shot. Instead, the arrow is likely to look a bit more crooked.