One of the most common reasons for a decrease in conversion rate is a change in traffic sources. This could be due to running ad campaigns on a new platform or targeting a different audience. Negative keywords can also lead to a drop in the conversion rate. The climate can also influence lower conversion rates, as bad weather can reduce search volume and increase cost per conversion.
PPC landing page optimization is an important factor, as an increase in page load time can reduce conversions. A decrease in traffic volume can also reduce the number of conversions and the conversion rate. Setting a single conversion rate can be limiting, and pursuing the top positions just to get more sales isn't always the best option. Conversion rates are essential for finding visitors who have converted into customers, and it's important to ensure that the text and intent of the page match both the text of the ad and the intent of the keyword being targeted.
Even an increase in traffic can affect conversion rates, as advertisers may reduce their budget in an effort to increase ROI.