Shutterstock announces payrise

Shutterstock has just announced their annual payrise. Shutterstock started off at a flat rate for everyone. Last year, only those above $500 got a payrise (from 25c to 30c)and now this year, they have gone to a multiple levels which rewards their bigger earners more. The new scale is as follows:

Your pay per download is determined by your total lifetime earnings:
Earnings per Download Lifetime Earnings
$0.25 Less than $500
$0.33 $500 to $3,000
$0.36 $3,000 to $10,000
$0.38 Over $10,000

I am in the 3rd band ($3,000 - $10,000)so this is a 20% payrise for me.

It is hard to complain at a 20% payrise but I still think they should change their charging structure more. Currently buyers can download any any size image for the same cost. I think that different sizes should cost different amounts of credits. For example, from their 30 credits per day, if they decide to buy a small photo, it costs them 1 credit but if they download a large file, it should cost them (say) 3-5 credits.