When responding to any request for use of your copyright materials, you need to consider a few things before agreeing or declining:
Let's be clear about the legalities of this.
There is no legal obligation upon you to agree to use of your materials.
The legal issues arise after you give consent.
You're bound by the terms of your consent.
You must fully understand the terms of consent you're giving.
The example below is a pretty typical scenario. The request was made for use of written and media materials on a website. No period of time was specified, no payment was mentioned, and the copyright owner isn't too sure about the website as a place for his material. The copyright owner isn't saying 'No', but giving his reasons for declining, and leaving the door open for a reply.
Request of permission for use of copyright materials
I refer to your request of (date) to use materials from my books Hirem Horem The Happy Gnome and Pirate Billy's Adventures on Toy Planet on your website PsychoDolls.com .
The following information is required, in writing:
Please note, I cannot give permission for any use of my copyright materials without this information.