Because search engines don’t read images, the alternate text attribute places the image to where it belong in image search engines and explain to search engines what those images actually are.In summary,the aternate text attribute is of two main importance
Generating tons of traffics means optimizing your blog post for search engines like google..A well optimized post could generate tons of traffic from search engine.But one important question that is worth asking is this what is the essence of using images on your blog post.That brings us to the whole essence of this blog post.Without you realizing it,those tons of images lying fallow on your blog have the potentials of generating lots of traffics to your blog on daily basis if the y are well optimized for image based search engines like google images
Accessibility – Blog visitors who turn off image on their browsers or those with visual impairement and are having the page read to them need alt text to understand what the image is all about.
SEO – the alt text is the only way a search engine bot see and gets to know what the image contains. It cannot ‘read’ an image by itself and relies on alt text. Additionally you can attract traffic from Google Image Search with well-optimized images.
Because images uploaded to blogspot by default do not have alternate text,this make indexing those images by search engine near impossible
Here are the few steps you need to take to add the alternate text attribute to your image
First upload the image to your post the normal way
While still editing the post,click on the image
Clicking on the image will give you several option as shown here
Click on properties
Clicking properties will give you this box
Enter your preferred alternate text and if you so wish enter the title text also
Click OK and you are done adding your alternate