When do you decide to stop promoting a sponsor?

[cheeks]

Hi,

I know a sponsor might work really well for some while it does really really bad for others.

When you guys notice that a sponsor is doing shit, do you stop promotiong him immediatly or do you do some changes such as:
-change gallery design
-change scene/thumb selection in tgp/mgp gallery
-some other thing..

I know finding a winning sponsor is difficult and I'd like to know if you guys persever in making the sponsor you choose work,
or do you simply change sponsor once you see it dont work with what you are currently promoting it with.

thanks alot.