I have a question. A client is reluctance with appending Coremetrics tracking parameters (e.g., ?cm_mmc=LS-_-1-_-2-_-3) to the end of these links citing SEO/duplicate content as one issue. I suggested that we appended such parameters in a cookie. From an SEO standpoint, having those parameters will create a dupe content problem. Are there any other solutions or workarounds that I'm missing?
you could use js to setup the final links (something like GA does) so spiders can't access them directly. And use a cookie to verify human presence.
The problem with having the parameters in the cookie is that you cannot manage the cookies easily because of the handshake and different params perhaps, as the server has to send the cookie first, then the client to send it back etc.
You can even do it without js (simpler), because you can identify the spiders and then you don't emit the parameters with the links in these cases.