Can a vendor have different commission percentages?

I'm looking to see if I can offer different commission percentages on products in the same vendor account.

I know that at one time, I used to drop my cookie and then direct someone straight to the downsell page and pitch it as a "secret discount." Personally, I don't REALLY mind if someone does that with my own offer, but I want to reward those who make bigger-ticket sales with a higher commission.

However, it's looking like I cannot do that. I could have sworn that it was an option at one time, but it appears to no longer be, or am I missing something?

Can anyone shed a little light on my situation?

I believe Plimus and RegNow offer custom commission % per affiliate, not so sure about Clickbank. One way around it might be offering a flat volume incentive paid at EOM/EOQ or something similar if they'll allow it.

I was thinking more on a per-product basis than a per-affiliate one. Thanks for the info, though!