Probably the avenue for monetization would be access to the back catalogues. Which in turn eliminates the free part of free stock photography.
While this may seem ludicrous (eliminating the appeal of your free stock photos over paid ones) this is common practice after a series of emails looking to elaborate on this point with a few of the services.
While this may seem ludicrous (eliminating the appeal of your free stock photos over paid ones) this is common practice after a series of emails looking to elaborate on this point with a few of the services.