Fotolia , again(!), have played the "Lets change to rules on the Quiet" game by increasing the number of images you need to sell to to earn a higher commission. It's understood that those who have already reach a 'ranking' tier will retain that rank even if the number of sales needed has increased above the number of sales they have made. A table of the new tier vales can be seen below along with the old values on the right.
Fotolia rankings today (left), against those previously (right)
(explanation of the fotolia ranking can be found on our fotolia review  page, but the above tiers vary the commission percentage you earn per sale, the higher the tier the larger the commission you earn.)
I've noticed a concerning number of these changes appearing on microstock sites without announcement, making changes without warning is bad enough but doing it on the sly without telling contributors about changes to the goal posts they might be trying to reach is pretty low which ever way you look at it.
This follows on from stockxpert's  change to their affiliate system, after a software upgrade last month affiliate links pointed to 'page not found', and affiliate earning stats have vanished from the site. Promises on the forums that visits were being tracked did little to alleviate concerns when the same problems were seen more than a month after they first appeared. Photographers who had stockxpert referral links on their sites were left no option but to replace them with those from another agency or join a new stockxpert scheme with significantly less favourable structure. (if they have noticed that the links no longer work that is!) No official statement was made warning of the changes, and from what I see none has been made since.
Last month fotolia also made changes to their affiliate scheme, dropping earnings from referred photographers, and while most photographers refer buyers to microstock sites (if anything) there were plenty that lost out from this change. The sudden change is one thing, but at no point did fotolia put out a statement that the system would change, nor was a message posted following the change. The change was only discovered after fotolia members logged into their account and noticed that referred photographers had 'expired'.
Comparing these changes to a recent announcement by macrostock  agency alamy: they have reduced the amount that their contributing photographers earn by 5%, they have given their contributors 45 days notice that this change will come into place on 10th Jan 2009. This too would be considered 'bad news' by photographers, and without getting into discussion about these sites need to remain profitable perhaps necessitating changes, it's reassuring to see that, good news or bad, some agencies announce changes to their commission structures before they take place.