Optimization plays a key role to rank your website higher in major search engines like Google, Bing etc. It helps you to brand your website through organic traffic. It is a good practise to give first preference to organic traffic than to a paid one because it helps you to analyse when to go for a paid one.
Apart from creating an attractive banner or a featured blog image it is equally necessary to optimize it. That can be achieved through image attribute like alt and also by naming the image with related keywords.
Setting the width(100%) and height(auto) properties of an image will make it as a mobile-responsive image.
Mobile responsiveness is also one of the factors to rank higher in search engines.
A broken image with no alt attribute leaves a viewer with no clue about the image. But with alt attribute filled with related keyword or name of the website helps a viewer to identify the content it offers even if the image is broken as your alt="keyword or name" is displayed after the broken image.
what i said above is only a brief info about image optimization. There are more ways to use your image properly in your website or blog.
img src="https://harvesttraffic.com/getimg.php?id=1" alt="Harvest Traffic Coop banner"
Can you see the alt name above?
This will be more useful when you write any blogs with more images :) Placing related keywords in alt and name of the image is simple but an effective technique .
Make sure to click the above banner to join :)