Warning: Incoming strange suggestion
Perhaps you could provide an ajax link allowing to reload at will just the homepage header (the image showing random manga titles, to be clear)...This suggestion comes from the fact that I often use the header to get ideas about new titles to read, so i have to refresh the whole page again and again...
Thank you, bye
just type F5 to refresh...
it's seems not so difficult to me...
The point is that it re-loads the whole front page thus more requests from the server etc. Costing him and us bandwidth and cpu cycles.