OK, I saw many times this behavior, but this isn't really an option unless it's done massively by all.
The example in history: When StockXpert was closed I felt really bad since I saw 1 out of 5 of really working agencies will be missing, but after months, my statistics show no drop in the global income from microstock. This means automatically that buyers at StockXpert were spread along the remaining microstock agencies. I don't think, buyers are stupid in searches and choosing the agency, instead they are clever than we (contributors) think. Also they saw the prices and the same images at agencies.
At StockXpert all our portfolios vanished into the cyberspace, regardless of we wanted or not, so everybody of us needed to live on the remaining options. Now, removing our ports from IS can bring us the support of the independent agencies (who are our future), true, not in one month (when StockXpert buyers were helped to migrate to other agencies), but our independent future is based on independent agencies.
Note that i'm not a sticked/paid member of any agency, I simply talk about facts. 20% is a shameless low payout.
If we disable our portfolios at IS, a lot of content will be available only at competitors. I don't count the exclusives and those who aren't interested, or doesn't read the forums, but in theory this move can help us a lot. Another problem is the timing when everybody of us does the same move to achieve maximum impact on both sides.
Opinions wanted.