I think a flat one time fee per access is fine, so long as it's proportional to the sales they make. Data has a value with respect to time anyway, new data is more valuable than old data, even if the data is the same, so it's not like they'll just be getting it one time.
I think a flat one time fee per access is fine, so long as it's proportional to the sales they make. Data has a value with respect to time anyway, new data is more valuable than old data, even if the data is the same, so it's not like they'll just be getting it one time.