Estimates are more reliable the closer a site is to being ranked #1.
Other wise this will affects your website negatively.If a site has Certified Metrics instead of estimated, that means its owner has installed code allowing us to directly measure their traffic.These metrics have a greater level of accuracy, no matter what the ranking. That's why you should use alt tag on your all pictures, which you use in your website. | Mehrsprachiger Online-Datingservice | Le service multilingual de connaissance | Tante lingue servizio di conoscenza | Servicio multilingüe de encuentros | ???????? If there is no alt tag, search engine doesn't understand anything from the image.