I got an email from WWF requesting permission to use my two photos to raise awareness about the importance of conservation and further their mission. Should I say yes? What is your view on this?

I got an email from WWF requesting permission to use my two photos to raise awareness about the importance of conservation and further their mission. Should I say yes? What is your view on this?
I think it depends on where you are in the professional aspect of your photography. When I was starting out, I donated images to NWF, DU and other organizations for publication. I used those national publications as a reference as I submitted queries and portfolios to sell images to other magazines. I rarely donate images anymore but I feel that my early donations helped to get the commercial end of my photographic avocation on the roll. One thing to keep in mind is that WWF, NWF and others are always paying other photographers good money for images on the next page following your donation. I remember a few years ago when Artie mentioned that Ranger Rick (NWF) paid good money for his images, I decided to cease from signing over all my NWF contest submissions for future publications, coffee cups, etc. I suspect you will get a variety of opinions on this issue, Troy, so enjoy the ride. By the way, I still donate many images to certain entities such as USFWS and Missouri Audubon each year but you have to strike a balance.
DB
I have given away many images for good causes like this. Life is too short not to. However, if they routinely pay then I would ask for payment too.
Ditto John's comment.
Who knows how many times in the future they may want free images.
What is their intended use? Advertising?
I am with Danny. If everyone donates their photos, why would any publications pay for pictures any more. I continue to donate my pictures to 2 specific organizations but that is it, esp when I am all too aware they are paying others for their photos. If they really want a photo, they will pay for it as they pay others.
Troy, I agree with the others. I've done some stuff with The Nature Conservancy, and they pay well and no questions asked. WWF is big enough that they have a budget for photos and, as Marina wrote, if we all give them away why would they ever pay for pictures again? If you had a longer-term relationship with them and offered a freebie or two on occasion, that would be different, but I think for a first-time image deal, you should require payment.
As for smaller/local organizations that don't normally pay for photos, that's a different deal as Danny mentioned.
Good luck!
Greg Basco
Working for non-profit conservation organization, I cannot tell you how important images that showcase nature via landscapes and plant/animal shots actually are in garnering interest. Few people seem get outdoors anymore, so anything you can show them to spark an interest is integral. Donating an image can help ensure that more donor dollars go to on-the-ground conservation. That said, it is the photographer's decision about making a donation, and you shouldn't feel pressured. Ultimately, if you do it, it should be because you believe in the cause of the organization and want to help out in that way. Perhaps you can donate the use of one and ask to be paid for the other. Just my two cents from the other side of the fence...
Take a look at WWF financials. That should help you decide.
Jim