Website Query

If someone wanted to use your photos on their website what would you charge?
To promote a product ...
To enhance the look of the site ...
For informational purposes
All the same or different prices?
Thank you

Hi PhotoBob:

They would all be different prices .. and there are are a few additional questions...

Is it a friend ? Big or small company? Well known or unknown product?
Is there a lot of "traffic" on the site or is it sleepy?
As you can imagine if it is a friend or a company that is small or a site with very little traffic you might want to charge less $$ than if it is a big multi national corporation with lots of money and resources thousands of visits a day...

Sorry for answering in the form of a question...
John