As I said, I am no expert, so can't say for sure. Sometime back, rather recently I read about
its a great case study on amazon affilliates, and this guy lists products that many say with 90% guarantee that no one buys, he lists the most weird products, still he disloses that he makes more than 20k US$ a month which is only 60% of hs revenue.
The cache policy I heard they store for 24 hours, now 90 days sounds a hell lot. Did you sign up directly or thru affiliate networks?
May be there is a difference in cache policy of Amazon.com and amazon.iin, if you listing .in products