Best strategy for category filtering links eg by colour

[blessig]

Hi All,

I hope you can help with some basic on page seo questions!

I have an ecommerce site which allows users to filter/restrict the view of a category by one or more colours.

This is done by appending a querystring value to the url ie to view blue, green and purple widgets the link might be:

www.example.com/my-widgets-category/?colors=123,92,64

On each category page is a group of coloured boxes with links to filter by that colour, (only if there are available coloured widgets in that category).

Each category has rel=canonical set to be the appropriate unfiltered category url ie:

www.example.com/my-widgets-category/

I used to have these colour filter links all nofollowed- but am not sure that this is a good idea.

So my questions are:

1/ what are the implications of these colour links that can generate a lot of different urls (as you can keep on adding colours to the filter) and how can i enure that i am not shooting myself in the foot- my customers love it!

2/ I also have page=1 etc appended for paging through results- the canonical url is set in all instnaces to be the plain category page as above- do i need to add the rel=prev and re=next?

3/ all of these links can really bump up my total page link count- at the moment i have colour filtering boxes in my main menu drop downs so that users can filter all the products that exists in all of the nested child categories of top level categories by colour. Should i remove these to reduce my total link count, nofollow them or leave as is?

Its a great site feature for users- i just don't want to be shooting myself in the foot unecessarily.

Thanks!

[blessig]

Well following on from Dr Petes timely blog i have done the following:

For all faceted navigation by color I have added  noindex,follow meta tags to remove these pages- i also removed the rel canonical tag from these pages as I was not sure that having a noindex and pointing to a vanilla category page as the canonical version was too clever.

I have modified my rel canonical to point to the correct page for all paginated pages.

Assuming the above is better than my previous state of affairs how can i solve the following?

My main category navigation has faceted filter by color links for each category. Tnis adds around 100 extra links on each page sitewide. How can i reduce the negative impact of having so many links in my global nav short of removing them? Can in use some sort of javascript to perform the navigation?

Thanks