Alt Tags as a SEO tool when defining Images on your web page
Creating SEO friendly Image Alt Tags
When adding images to your web site and web pages as a good SEO practice you should always include a descriptive and targeted alt tag description to describe the image.
This is a textual description that relates and defines the picture you are inserting. Alt Tags became the standard to help with user accessability. Blind or partially sighted internet users sometimes use web readers to "speak" the content of a web page.
“Image Alt Tag's - Well written alt tags are a definite SEO must! Experience and care is required as you have to ensure they stay relevant and are not considered to be spam”
In the early days of the internet this led to pictures being pretty much ignored. By adding an alt tag then you are providing a description of the picture and text that can be read instead of being able to view the picture.
With the increase in image data bases within the search engines eg Google Image Search, these descriptions can also help with the search engines bringing traffic to your web site - One of our client wedding dress shop clients receives a lot of traffic via correct alt tag labeling of the wedding dresses she showcases, now these aren't always going to result in physical sales but it is driving relevant traffic and increasing that likely hood as once they have seen a well designed site these visitors then navigate the other web pages to see the other dresses she has on offer.
Image ALT Tag's a Warning
Many SEO companies or inexperienced web coders will use the alt tag as an opportunity to keyword stuff. This is not a good working practice as it is not providing any benefit to either human or spider visitors and is definitely considered a black hat technique by the search engines so is something your web site search engine positioning could suffer from.
Remind yourself of other SEO Black Hat Techniques to avoid here