Except for Chrome, and firefox users who have explicitly configured their cache size, most browsers have a very limited cache, with the average sizing being ~50MB. For everything. I don't know about you, but I've loaded 50MB already today. Because of that, I don't worry about cache hits, because the median visitor will have nothing cached. Instead, worry about total page size, and total number of http requests. Minifying dramatically helps the number of http requests.