Below is an email I just received from Linkconnector merchant All Pro Atv's:
We would like to update you on our new commission adjustment for our /All Pro ATVs/ campaign we have with LinkConnector[2]. The ATV business is growing more competitive everyday, so we will have to reduce commissions to
2.5%_ to remain competitive

Here's my response:
I understand that your business may be getting tough but taking it out on hard working affiliates is a bad marketing decision. I don't know why any affiliate marketer would bother wasting their time for 2.5%.
I'm sure you know that there are 1000's of affiliate programs out there and many offer more then the tiny 2.5% commission that you're generously offering.
If I'm going to spend time and money promoting a program, why would I waste my time on your program?

Sometimes it may better for a merchant like this not to be in the affiliate marketing business. If I sell a $650 ATV, I will now only get $16.50. Nice isn't it.
This is just my thoughts but it annoys me when a merchant reduces their commission structure. I feel penalized when they do this.