How much does Google dislike dynamic URLS?

Does Google simply disregard URLs to directories that robots.txt forbids?

[robspooner]

We're having a little internal debate on a simple question. We know that Google has reservations about dynamic URLs. On our site, the only dynamic URLs we use are to direct traffic entirely away from our site for affiliate deals, so we agree with Google completely. We also don't want them indexed or even spidered.

To ensure this, we have placed the directory with the dynamic ColdFusion pages in a specific directory, which we have identified through robots.txt as "do not index." We're assuming that Google respects our wishes.

The debate is over the impact on PR. Suppose page X has four links out, one of which is a dynamic URL that goes to this forbidden subdirectory. There are thus only three links to indexable pages. Is the PR of page X distributed to these three as though there were only three links on the page, i.e. 1/3 to each? Or does Google downgrade them because there are four links physically on the page, and thus distributes only 1/4 to each of the three, with the 1/4 that might have gone to the forbidden URL instead just vanishing?

[doc_z]

Hi robspooner and welcome!

Google takes all 4 links into account, i.e. even if a page is not (cannot be) indexed it receives PR.

[robspooner]

In other words, these links will bleed PR into empty space, since the unindexable target page can't be examined and hence can't possibly pass PR along.

If this is true, then a large site with a lot of affiliate links on each page, even if they pass them through a script in a do-not-index subdirectory, is going to suffer a huge PR loss. It means that the "oh, why not," kind of minimal affiliate deals probably cost more than they bring in.

[sullen]

In my experience Google doesn't "dislike" dynamic URLs - it seems to follow them as much as any other link.

So I agree that the pages will get their share of the PR.

However, the impact of that might not be as great as you think - firstly, Google estimates the PR of a lot of pages and secondly, the PR "bleed" will be so minimal as to make no difference at all.

[BigDave]

If you are leaking a lot of PR to those links, you need to re-examine your internal linking structure. You are talking about 3 or 4 links per page, but an average page on a reasonable sized website will have well over 20 links to internal pages just with standard navigation.

So if you have 30 internal links and 3 external (affiliate or not), you still end up with 90% of the PR getting recycled back through your own pages.