In Bangladesh, we usually get lots of query from different ecommerce owners. They typically have some questions that we reply via Email and phone conversation. You can send your own query too! For the large audience of Ecommerce Owners of Bangladesh; I have just found the most asked question along with some suggestions against it that anyone can follow.
Duplicate content must be the great barrier of staying on SERP. This problem may be fixed by modifying design and code. Using URL parameters and session IDs are worst matter in case of e-commerce websites.
E-commerce sites are not always optimized for googlebot actually. Some internal issues found on schema.org. You may use such types of URL since this will ensure of accessing your data. Nowadays many e-commerce sites do not maintain these tricky issues. Just because of they are facing of de-ranking problem.
You can take advantage of google products if this search engine exists where you want to rank. In google product search, sites owner usually upload their products. In your adward account you need link these feeds. Respecting the proper algorithm of it you can simply rank your site.