Hi there, Most websites have a logo on top of the page. Do you link that logo to index page? Do you place alt tag of the homepage or relevant to current page (which might have different topic)? What is your way?
I place an ALT tag, and link it to the homepage. EDIT: My ALT tag usually has the company name and services in it, so it's rather broad. The logo ALT tag is a good way to keep a cohesive keyword theme running through your site.