A question for you. I have been using supercahe on a site which had this load. (It is a VPS)
Load 0.8 / 0.86 / 0.44 ( 1/5/15 minute load) and was all working great but then the ad agency wanted me to add a really simple tracking image so they can see whenever the homepage gets loaded for their stats programme.
BTW already have google analytics so we know what that is and can see all of the traffic sources.
Anyway they complained that the tracking image isn’t working. I suspect it is because of the caching.
For a test of my theory I have turned off the caching over night to see if their readings improve but it would be faster all round if we can do both.