If a create a dataset for $100 I could sell it to one person for $120, or 6 for $20 - I make the same even if the value to each individual client is reduced; on the other hand, the value to each client versus* making their own is (120-100=) $20 in the first case, but (120-20=) $100 in the second, so fewer clients are likely to "roll their own" competing datasets.
And to clarify the last point:
If a create a dataset for $100 I could sell it to one person for $120, or 6 for $20 - I make the same even if the value to each individual client is reduced; on the other hand, the value to each client versus* making their own is (120-100=) $20 in the first case, but (120-20=) $100 in the second, so fewer clients are likely to "roll their own" competing datasets.