can/does adding a shopping cart effect ranking?

[Penrod]

Can a shopping cart adversely effect ranking? Either by slowing down the response time in somecases or by having "pages" within the site that are not search engine friendly?

[Whitey]

Definitely and possibly.

Definitely - If the shopping cart is indexing duplicate content, then this can lower the rankings as those pages fall in page strength and drag the overall site strength/score down, or even tank the site completely. Check out the discussions on Hot Topics here : [webmasterworld.com...]

Restoring the site can become complex and I've seen many webmasters just give up. So best to read the thread thoroughly - I hope it helps you.

Configuring the site to have one version of content is likely to be critical and many "out of the box " shopping cart and forum software solutions are defective for SE indexing purposes.

Possibly - With regards to the website's speed performance, there appears to be some opinions around the place that Google does take into consideration the speed of a site, however , I'm not sure that most sites would be effected so long as the response times are within acceptable limits and not timing out. But some better heads than me can probably thow some light on this.

[ecmedia]

I am not sure that it should matter. Having a few bad pages should affect mostly these bad pages rather than the whole website if the website is otherwise an authority.