I have actually noticed that some affiliate networks and even the individual affiliate departments of the advertisers themselves will talk differently to you if you are making them money or not. A couple make it real obvious that if you are a top affiliate or advertiser you will get treated better than if you aren't.
Shame it has to be that way with some, especially since they never know who is going to wind up being a super affiliate or advertiser one day!
This is always the case every where, no one wants to harm there revenue stream. The more powerful a client you are the better deals you can cut with with your business partners. When I owned a pet food store, the more I sold, the more I was able to get "Special Contract Pricing" from the distributors and manufacturers. With the special pricing, it made it much easier to sell their products. When my credit card processing went to 80,000 USD a month, I was able to get my rates lowered, who wants to lose 3% of that a month for doing nothing? So 3%, becomes 2.5%, just like that. All those processing fees get waived - "Gateway fee, Service Fee", Batch Fee, Report Fees" - Gone.
It's just the way it is.. It's a struggle to break the barriers, but once you break the barriers, things become so much more easier.