Years ago I worked in graphics and found it was common for a paper vendor to say to a printer, "I'll give you the ten thousand pound price on everything you buy if you buy all your paper from me."
The same type of arrangement in stock sales, coupled with the fact that agencies honor each others' bulk-rate deals, is the main reason I chose to opt out of Distribution. This evidently takes time to take effect, since there have been two distributor sales so far this month. However, one of them was for a quarter of Alamy's book rate for use in TV ("Quantity discount. Flat rate per image.") The other went for a [paltry sum] for a full page in a magazine (plus digital).
I may opt back into Distribution next April, and/or make a different decision about submitting to multiple agencies, but for the moment I continue to think that working exclusively with Alamy is the best way to keep the price per license at a reasonable level.
edit: removed specific amount
Edited by DDoug, 2 weeks ago.