Forum Moderators: martinibuster
1) Visually handicapped users with screen readers won't appreciate lengthy alt text; and...
2) In theory (and maybe in practice), stuffing alt text with keywords could affect your search rankings.
In my experience, the best way to make photo galleries work with AdSense is to use descriptive pages titles and captions. (My CPMs with photo pages are usually pretty bad, though--about a quarter of the site's average and a fraction of what I earn from some pages and subdirectories.)