yeah the amazon product API has some severe limitations. I have 25,000~ books on my site, and I just don't have enough API calls in a day to keep the prices 100% updated. It's on my todo list to revisit this, but it's low on my priority list. I don't make that much from amazon refs(couple hundred a month)
I will say that I don't think they really defend their TOS too much from my experience. I used to have a cookbooks site for years that used the same affiliate tag i use for my greatest books site, and never had any issues.
I will say that I don't think they really defend their TOS too much from my experience. I used to have a cookbooks site for years that used the same affiliate tag i use for my greatest books site, and never had any issues.