The way I see it, if everyone was paid to contribute, the database would be unaffordable. And for the effort, an expectation of being paid for the time is reasonable. I dabble in coins. We all volunteer our knowledge to have standardized publications that are the buy or sell 'bible' of the coin world. It takes a paid crew of 4 about 18 months or more to assemble and check information for just one segment of coin collecting. Once published, they're not cheap but if every contributor was compensated, nobody could afford the physical books or online subscription rate.