Product feeds, especially from big brands, are poison to your site. To overcome the problem you need to have a good amount of backlinks and real users. Expect to need to pay for traffic at first if you use product feed text. Number of pages indexed has very little to do with traffic, it is possible for a one page site to get more traffic that a 1 million page site.
Interesting fact: The former head of ebay partner network, whom has been promoted to a global position recently, used to run his own shoe related affiliate site as well as his own online business before working for ebay. That business did nothing but create unique product descriptions in bulk. In other words he knew that generic descriptions have been a problem for a very long time now.