Your webshop has 250 products and site: query shows 7500 URLs indexed. What is the likely cause?

[mattcutts]

i will give the options also.

1. canonicalization Problem
2. Exposing Session IDs to Crawler
3. Pagenot found error page may not be returning a 404 status code
4. Site is hacked
5. Any of these

[Azzi]

Its very tough to tell, but would tell to check your site map in google web master and also check with the error pages.

[Jhon]

Exposing Session IDs to Crawler - is the correct answer for this

[Sidhaanth]

it is canonicalization Problem and it also Crawler you site IDs.

[swami]

Exposing Session IDs to crawler