How Site Speed Affects Sales: Performance in Numbers
A 1-second delay means 7% conversion loss. The real cost of speed for SMB sites and how to fix it.
Published by: Hızlı Yazılım
Speed is not comfort, it is revenue
A slow site is a shop with a door that sticks. Nobody wonders what is inside; they walk into the shop next door.
Google’s Core Web Vitals thresholds draw a clear line here. Largest Contentful Paint should land under 2.5 seconds, layout shift (CLS) should stay below 0.1, and interaction delay should not exceed 200 milliseconds. These thresholds are not arbitrary; they were derived from real user behaviour.
On mobile, every extra second increases the number of people who give up. And the loss is silent: nobody ever tells you they did not buy because the site was slow.
The picture in Türkiye
The field reality is that a significant share of SMB sites take more than five seconds to open on mobile. The causes usually fall into the same three buckets.
Unoptimised images. A 4 MB photo uploaded straight from the camera will finish a page on its own. The same image in WebP at the right dimensions can be 150 KB.
Bloated themes and plugins. Ready-made themes bring dozens of features you never use. On an installation with twenty plugins, every page downloads files it does not need.
Weak hosting. On oversubscribed shared plans, the server’s initial response time alone can eat seconds.
Where to start
Measure first. Put your site into PageSpeed Insights and look at the mobile tab — the desktop score will mislead you. Then work in this order.
Images. Move to WebP, serve them at their real display size, and lazy-load anything below the fold. On most sites this step alone halves page weight.
Fonts. Every font family pulled from Google Fonts adds a connection and a wait. Serve fonts from your own server and load only the weights you actually use.
Render-blocking files. CSS and JavaScript not needed to paint the top of the screen should be deferred.
Caching and compression. Brotli compression and correct cache headers on the server produce measurable gains without a single code change.
The SEO side of speed
Speed alone will not put you first; content and authority still weigh more. But Core Web Vitals is a tiebreaker between two pages of similar quality.
The real effect is indirect: a visitor who bounces off a slow page signals to Google that the result was not useful. Accumulated, that behaviour drags the ranking down.
Another practical point: Google also spends time crawling you. On a slow site the crawl budget covers fewer pages, and new content gets indexed late. On a 200-page industry site, that difference is noticeable.
A realistic target
Making every site score 100/100 is neither possible nor necessary. The meaningful target is a mobile PageSpeed score above 90 and a real-user LCP under 2.5 seconds.
We run this measurement before launch on every project we deliver and hand the client the result in writing. Ask for the same when you take a quote: “what will the mobile PageSpeed score be at handover?” A provider who cannot answer that with a number has not thought about speed at all.