Sometime in the last 6-9 months (it's been that long since I last looked at my account), Amazon changed their policy on placing an upper limit on the amount an associate can earn on big ticket items:
Only personal computers (both desktops and laptops) have referral fees capped at $25. No other product lines have their referral fees capped.
Previously, the most you could earn if a referral was $10, even if the item cost $3000 and the referral rate was 5%. Sometime in the last month and a half, someone used my associates code to purchase a printer for close to $600 and gave me $28 for "selling" that printer for them. I don't link to Amazon as much as I used to (my referrals and revenue have been flat several quarters despite increasing site traffic), but the associates must be pretty happy with this change, particularly those that can move big ticket items on a regular basis. For the right blog or site, the revenue generated by putting up Amazon ads featuring more expensive items might compare favorably to using AdSense or the like.
So, if you've been waiting to buy that Segway, a book on Bhutan, a 65" plasma TV, or a 5-carat diamond, you know what to do. *nudge* *nudge* *wink* *wink*