BeerBorg

A bit scientific but it seems most of the oils are released in just one day and decrease after day 4. It doesn't mention much about which is the best way to keep the hops 'infused' in your beer.
I continue to work with this but my beers have a pretty good aroma and I find 5 days works well for me for MOST hops. Sometimes 5 and 3 day drops work good too.
Linky

I've seen articles that had such conclusions. But I've done short dry hops with unsatisfactory results. I think I'll keep mine longer.

Honestly, it probably depends on a lot of factors. Different hop compounds are going to come out at different rates. All are affected by PH, wort temperature, the amount of alcohol present (alcohol is a solvent that will extract different things at different rates then the water in your beer). So really your mileage could easily vary depending on the wort composition of the beer your dry hopping, and also the hop varieties your throwing in there, and what exactly you are trying to get out of those hops.

The thing about organic chemistry is that it's not linear. So any little change can muck up your whole theory. The article kind of gets into this, but in trying to "keep it simple" (sorta) this isn't really explained fully.

Linalool makes me Drool...