What are the implications for campaign performance when the landing page experience is not optimized for Japanese mobile users despite strong ad copy?

When strong ad copy on Yahoo! Japan directs users to a landing page not optimized for Japanese mobile users, the implications for campaign performance are significantly negative, resulting in lower conversion rates, increased bounce rates, decreased quality scores, and wasted ad spend. Japanese mobile users expect a seamless and user-friendly experience on their smartphones. If the landing page is slow to load, not mobile-responsive (difficult to navigate on a small screen), or lacks clear calls to action, users are likely to abandon the page quickly, leading to a high bounce rate. A high bounce rate signals to Yahoo! Japan that the landing page is not relevant or useful, negatively impacting the ad's Quality Score. A low Quality Score increases the cost per click (CPC) and decreases ad visibility, reducing the overall effectiveness of the campaign. If the landing page is not in Japanese or contains poor translations, it can confuse or frustrate users, decreasing trust and reducing the likelihood of conversion. For example, if a mobile user clicks on an ad promising a discount on 'スマホケース' (smartphone cases) but lands on a desktop-formatted page with broken Japanese text and difficult navigation, they will likely leave without making a purchase. Mobile optimization includes fast loading times, responsive design, clear calls to action, and easy navigation. If these are not accounted for the campaign will likely fail, with lower conversion rate, increased bounce rates, and a decreased quality score. This diminishes the ROI of the ad budget.