My ecommerce web site is listed in the major search engines, and has been for 2+ years. I originally submitted the site (using software) every 3 months or so but haven't in the last year.

My question is: If I am already listed in the search engine, what, if any value is there in resubmitting periodically? My site IS updated very frequently (weekly), but don't the search engines use spiders to recrawl sites that are already listed with them?

Thanks for any thoughts!