we are always wailing and complaining about our sites bouncing around in the SERPs, but i never notice the big sites dropping (unless they are specifically targeted for a particular reason, like eHow)
everyday few days i check my positions in the SEPRs and i always see the big sites in more or less the same places. maybe they drop a place or two, and the next week they rise again, and stuff like that, but they basically keep the same level all the time.
so at what point does a site become big enough to be immune from SERP changes? because it must happen. once you reach a certain size and traffic threshold, then im sure you are pretty much safe from the changes that the little sites experience.
have you ever owned a site that has achieved it? what kind of traffic are we talking about to do it?
let me just say that my site is pretty sizeable, but certainly not big enough to be rock steady in the SERPs. so i am not one of these sites that im talking about. although i haven't been hit be anything major for a good long time (touch wood).
