Less individuals are trying out Microsoft Bing search engine, according to a study released by search-based online advertising network Chitika.

The report shows that the Bing’s share of search impressions has declined at a steady rate, when looking at network traffic from August through the first half of October. The number of users coming through Microsoft’s decision engine has declined much more quickly.

In August, over 8.24% of search engine users and 6.7% of search traffic came from Bing. Since then, Microsoft’s impressions share has dropped to 5.44% and the user share has decreased even more significantly to 6.28%, the study reported.

According to the study, the impressions share of Google was 81.8% in August, and 84.19% in September. It was 84.99% in October. Yahoo! impressions share has dropped to 7.26% in October, compared to 9.08% in August. Google’s user share has increased from 79.86% in August to 83.82% in October, while Yahoo!’s user share was down to 7.42% in October from 9.36% in August.

The firm stated that the Bing’s advertising campaign had a very positive effect over the summer, convincing users to try out Bing, but seems to have failed to retain users who came over.

The results are based on a sample of 579,555,134 impressions and 273,537,852 users across the Chitika network.