Affiliate tag in blogroll link - still valuable?

[staffjam]

We have just launched an affiliate program for our service and quite a few sites are keen on signing up.
One of the ways they can subtly send traffic to us is via their blogrolls and so they put our link.

What i'm wondering is will this have any SEO benefit?

For example - the website homepage is abc.com
The link they have will go to:http://abc.com?p=8

Will this just be discounted by the search engines or will it still carry all the weight it previously would?

Thanks for any advice you can offer.

[robzilla]

Do you have rel=canonical in place to direct search engines to the authoritative page (in this example, your homepage)?

[staffjam]

robzilla - no there is nothing in place. The link will go directly to the homepage anyway. They are all linking to our homepage. They are quite happy to send traffic there as we have a very high capture rate of visitors details.

[linkbuildr]

Those links should bet set to nofollow or you're eventually going to have a problem

[FranticFish]

As linkbuildr says, according to Google's TOS these are basically paid links and should therefore be nofollow. To allow PR to flow through them could set you up for a penalty.

[robzilla]

robzilla - no there is nothing in place. The link will go directly to the homepage anyway. They are all linking to our homepage. They are quite happy to send traffic there as we have a very high capture rate of visitors details.

That's fine, but if /?p=8 serves the same content as / then you should 'merge' those pages, as it were, with rel=canonical.

[Robert Charlton]

The link will go directly to the homepage anyway. They are all linking to our homepage.

staffjam - These may look like the same page, but they're the same content under different urls, which means you're creating a bunch of dupe content.

Each different url is in essence competing with the others.

So, they're not going to help you unless you 301 redirect them to "/", but that would look spammy to Google because it would appear that you're trying to consolidate PageRank, which is in fact what you would be doing.

I would nofollow all of the links. Then using the rel=canonical, as robzilla among others suggests, is probably the simplest way for you to handle it.