Wrong! For a new product we started to develop I built a microsite. It resides in a virtual server with the same IP-address as our main site and 2 other sites indexed by Google. It has to a small portion identical content than the main site. And it's a dynamic site usin index.php+parameters.
There was only ONE link from our main site (PR5) to the new site. Nevertheless it was spidered within the same week and showed up in the SERPS the following week. Today, even though not top ranking, it's on the first page of SERPS for almost all important keywords.