Are URL rewrites still necessary?

Will traffic be affected if URLs include symbols like? and %

[Musicroom]

We run an ecommerce store which is a database-driven site, hence it has a lot of dynamic pages. A few years ago we realised that the problematic symbols (?,% etc) were making it difficult for certain spiders to index deep into our site, so we put a redirect onto our URLs and this dealt with the problem.

However this makes it difficult to get certain reports we would like out of Webtrends, and generally annoys my technical team. Google never really had a problem with the URLs as they were pre-rewrite. The question: is there any need for rewrites on URLs? If we were to revert to the old ones, would this impact our traffic levels?

[DaveAtIFG]

Welcome to WebmasterWorld, Musicroom! :)

is there any need for rewrites on URLs?

I suspect there is for SEs less sophisticated than Google, but I have no recent evidence.

If we were to revert to the old ones, would this impact our traffic levels?

Absolutely. You would break all existing links from directories, lesser SEs, bookmarks...

[ThomasB]

From my experience there are still some SEs out there that don't like more than 1 or 2 parameters. If you have just 1 parameter to add you could remove the rewrites imho. But I'd do 301-redirects instead of just removing. Because you would probably loose visitors as Dave already pointed out.