Crawling customer reviews from Amazon I want to know if there is any way that I can crawl customer reviews for particular products from amazon without being blocked. At the moment, my crawler is blocked after a few times. Any idea will be appreciated.
You are getting blocked because people do not want to waste server bandwidth on someone who is trying to exploit it without bringing significant profits. 

Try to make your crawling less predictable. 

Slow down the frequency with which you ping the server and vary the actions of your crawler. This will make it harder to detect as it will act less predictably and may be wrongfully identified as being a very quick human.