More Than One Site

If you have more than one site, link them together so your
sites share traffic. Some Webmasters believe that having
more than one domain for their single site increases their
search engine ranking, but they are wrong. Crawlers usually
only index information once, and so that just may be a
waste of your time and money.
However, if you do have more than one complete site, by
linking them together, you can increase traffic to both, and
by doing that, raise your ranking. There isn’t any magical
formula to increase your ranking, so if it seems easy and too
good to be true, like in life, it probably is.