Yep, I got approached too.
They're just another company trolling for free images trying to take advantage of novices and do-gooders.
What value would getting credited have? It might have some value if you're doing a marketing blitz trying to get your name branded everywhere but for a stock shooter or most Flickr users? I don't see any value.
Even worse, I remember the message was a bit misleading. There was some wording about "we don't pay for your photos but our service is free of charge to readers". As if to imply they don't make money so neither should you which is BS. They left out the part about "we do make a ton of money charging [whoever their customers actually are] and your images add a lot of value".
