You can optimize images on your website pages to get your site ranked better for different keywords, as well as better ranked on Google image search or so. As an example lets take this piece of code: <img src="myImage.gif" /> You can optimize this as follows: - Use Alt Tag with Keywords <img src="myImage.gif" Alt="Free Classified Ads" /> - Name images as keywords <img src="Free-Classified-Ads.gif" />
Definitely worth the effort. I have a lot of pictures on my sites and therefore visitors via Google image search. I don't care how they get to my site, once they're on the site they have a chance to look around.
you mean SEO optimization or size/quality optimization? for SEO I'd say use descriptive keywords and vary the text of images throughout your page. other than that I've heard it doesn't matter too much but am not sure.