Hello, I'd like to ask an advice to who work in microstock sector from long time. how do you interface with, for example, companies, airports, railways or ports for request to be able to take photos or videos for microstock use? To be more precise, let's assume I want to make stock photos or videos where railway do train maintenance, how can I approach the railway company to ensure that give me the permission to let me in to take photos or videos?  I mean, putting myself on the side of the manager who will receive my request letter, he will certainly ask himself: ok well, but what do we get us from this shooting service?

So, which advices for write a good request?

Thanks for replies,
Sergio