Here's what I've been working on lately. Mini-books. 14 x 14cm, one photo per page. Date & caption under each photo. Nice, thick, matte cover with full page print.
Each mini-book is 60 pages. It would generate automatically once you get 60 photos on your account. Then another one after 120 pics, etc. The last one would have 65 pages. So over the course of 365 project you'd get 5 mini-books.
Print quality is the same as in the regular books. But there's something special about the minibooks. These are really cute and nice to hold.
Unfortunately, right now I can't get to produce them under $12.50 per 60-page book. A bit steep, so I won't even bother putting them on sale.