Web traffic growth may be easing, as Adobe Digital Insights’ Advertising Demand Report found that organic web traffic in North America is saturated, with only 0.1 percent growth over the past 42 months. While six out of 10 sites saw traffic grow on average by 1.1 percent each month, nearly four out of 10 sites saw traffic decline at a higher rate, 1.3 percent.

The sites that reported growth between second quarter 2013 and second quarter 2016 drew 36 percent more traffic from personalized ads via email, paid search, social and other channels compared to shrinking sites. The data also shows that seven out of 10 smartphone visits now come from ad channels.

“The days of organic website traffic growth are reaching an end,” says Tamara Gaffney, principal analyst, Adobe Digital Insights. “Marketers need to prioritize personalization of cross-channel ad content and truly focus on mobile advertising or face declining traffic to their branded properties.”

The analysis of web traffic and ad trends from Adobe Digital Insights, software provider Adobe’s digital marketing research arm, is based on anonymous and aggregated data from Adobe Marketing Cloud, which collected 800 billion visits to 800 North American websites across vertical industries between January 2013 and June 2016. Complementary survey results are based on responses from more than 1,000 U.S. consumers, covering perceptions around digital advertising and ad blocking.

Adobe’s research found that across industries, ad channels account for varying traffic levels. Media and entertainment websites saw the most ad-driven traffic (72 percent average share in second quarter 2016) while the retail sector shows the biggest traffic gap between sites that grew and those that shrank – 72 versus 63 percent share respectively. By combining multiple tactics into the marketing mix, online retailers that experienced growing site traffic drove an average of 17 cents of revenue per visitor, seven percent more than those retailers that saw shrinking web traffic.

The survey also found that 68 percent of U.S. consumers feel ads have improved or stayed the same, with 57 percent saying marketers are running interesting ads. While 78 percent of consumers like personalized ads, only 28 percent feel they are appropriately customized. Highly personalized ads that are consistent across channels enable advertisers to mitigate ad blocker adoption. The U.S. ranks in the lower half compared to Europe in terms of current desktop ad blocking penetration (18 percent). However, global monthly active desktop ad blockers have grown four times over the past three years to 220 million. Among U.S. consumers surveyed, 44 percent using blockers find desktop ads annoying and 89 percent plan to continue using an ad blocker.

For more on Adobe’s findings, the full Adobe Digital Insights Advertising Demand Report can be found here.