I have my main site. I also have two secondary sites. In addition I have the following: Myspace Youtube Facebook Hi5 Squidoo Lens Blogspot blog Wordpress blog to market my site. It also gives me the oppurtunity to cross link and promote my main site. For example on a particular blog, I have links to all the resources I just mentioned plus my 3 domains. Someone recently told me this is borderline black hat. How is that possible? Second question - What are some other means of marketing my site?
Google wants backlinks to be natural "votes". Reciprocal links, link exchanges, and cross-linking are not natural links. Google wants you to add "nofollow" to the links if you need them for traffic. Google is getting a lot better at detecting owners "voting" for their own sites. At some point, it looks like a link farm made to rig the rankings. If google deems that to be one of your sites, you will get a penalty. Crosslinking your own sites that share the same whois information or are with the same host are the easiest to detect automatically. You have to build links to those other sites for them to have any link juice. A blogspot or wordpress blog with no incoming links isn't going to help any site you link to. If your site ever starts ranking in the top ten for a highly competitive keyword, you then have to worry about your competition reporting ever single thing they think you did to rig the SERPS. I know this from experience. When you get to the top, there is always someone who wants your spot. The more legitimate your backlinks, the higher quality your site, the less you have to worry about.
That's black hat, spam... it depends on the point of view. Google doesn't like these things a lot. Try to keep the cross-linking as natural as possible.
For some, it helps a little, although it's still not natural/organic. but seriously... Google knows what you're doing
I agree Google wil use whois information to identify spammers and reduce the prominence of your sites in serps. Kepp it natural and do some blogging to get natural links