You guys have been great answering my questions so far. Here is another that has come up. Let's say there is a company with 2 or 3 sites, selling the same type of product but for different markets: ie Home widgets, Professional widgets and perhaps Niche widgets. The products aren't all going to be the same, some being professional grade and some for home users, but the categories are pretty similar. Would it make sense to link between the sites. They already mention the sister sites on each page of their websites, which concerns me. What if on the category pages they had a link that said something like this. This is our selection of professional widgets. We also have (home widgets) and (niche widgets) with the links going directly to specific categories.