Speaking only for myself, I discuss the planned uses that the client forsees
and get a rough idea as to distribution of the image, etc. I then plug this
anticipated usage into a chart of rates, based primarily on ASMP usage fees.
If the client needs exclusivity beyond the anticipated print run (or Web use,
or similar), that is a little extra. If the client doesn't know how the image
will be used, I offer to sell them unlimited reproduction rights, for an
unlimited time, to the image, and add in any additional exclusivity (beyond 1
year from invoice date), that they may need. Other considerations are possible
use outside US (where I'm based), potential stock sales by client (which I
limit when doing the contract, but will sell if client has market), and any
other additional aspects. Most clients like the unlimited/unlimited rights, as
they don't have to worry, should the image be used again, and again. All of
this is figured into the "photography fee," and is specified to the client.
Since most of my work has limited stock value, I have no problem with doing
business this way. I can still sell as stock, after the expiration date of any
exclsivity, and just don't worry that the image might have "saturated" the
market by my client's use. If they can use it many more times than they
originally anticipated, without any hassles, I see it as an increase in value
to the client.

Some photographers take an all together different route, only selling the
image per a specific use, with any additonal press runs, ads, etc. costing the
client more.

For pure ad, non-collateral work, some shooters just stipulate a % of the ad
budget and are done with it.

So, it differs from shooter to shooter.

Hunt

Have a look at (and wade thru) http://media.gn.apc.org/feesguide/photo.html

It'll give you a pretty good idea.