Google was quick

[miles]

Last week my new site, about 1.5 months old, has page rank 6 on all but 3 pgs. I was surprised in a that was quick attitude. I did not take too much time to build the site for google and its doubled my traffic. I saw a peek in my traffic in an hour after I noticed a refer from google when I checked my log analizer. Does Google generally index a site this fast or was it a fluke? And second how long does a page keep its rank? Assuming nothing changes.

[EliteWeb]

I've experienced something also of the nature, but 1/2 way through the month it started coming in and out every other week. Upon the next update I made it in fine :)

[stuntdubl]

I also have a relatively new site with a PR of 5. If for whatever reasons, I did absolutely nothing to the site, would my page rank stay the same, or because of google's algo would my PR be reduced??