NEW YORK: As the value of programmatic advertising continues to come under scrutiny, it has emerged that JPMorgan Chase has slashed its digital advertising to just 5,000 pre-approved sites without seeing much change in the number of impressions the ads received.

Until a few weeks ago, the global financial services giant advertised on about 400,000 websites a month, but its massive cutback has not hit performance, according to the company's Chief Marketing Officer.

"It's only been a few days, but we haven't seen any deterioration on our performance metrics," Kristin Lemkau told The New York Times, as she confirmed JPMorgan has seen little change in the cost of impressions or the visability of its ads.

Lemkau explained that JPMorgan checked those 400,000 website addresses over a 30-day period and discovered that only 12,000 (or 3%) led to activity beyond an impression.

A member of staff then manually clicked on each of these web addresses to double-check whether they were ones that the company wanted to advertise on.

And after eliminating 7,000 that did not meet JPMorgan's requirements, that whittled the total down to just 5,000 sites.

"Before the YouTube thing happened, we were just looking at programmatic," she said. "Now the question is, what else is out there that we should be looking at whitelisting? At some point, a human is going to take a look."

According to Eric Franchi, Co-founder of adtech firm Undertone, the development could hit operators of smaller websites as well as adtech companies if other advertisers follow the same route as JPMorgan.

"If you charge a percentage of all of the ads that run through your platform, then the prospects can be pretty dim if all of a sudden your volume has been cut by 95%," he said.

"So many of these companies, and some of them are public, tout the number of ads they deliver per second, per day. If you start seeing more marketers move in this direction, it will be pretty interesting. What are the metrics then that those companies start to report?"

Data sourced from New York Times; additional content by WARC staff