Google ranking tips from a Google’s Matt Cutts

Last week, Google's Matt Cutts had a Q&A on the SearchMarketingExpo in Seattle. Here's a summary of the most important statements:

Paid links:

Google considers buying links to be outside of their guidelines and they might take strong actions against that in the future. Matt Cutts indicated that "Google might take action" if webmasters buy links anyway.

Outbound links:

Matt Cutts said that links to other websites are good for users, and therefore good for search engines.

The impact of spammy domains that are owned by the same person:

Matt Cutts indicated that a webmaster who owns many spammy websites might get trouble with his other websites.

Google's supplemental index:

Pages in Google's supplemental results are parsed differently than pages in the regular index. Pages from the supplemental results can get into the main index. According to Matt Cutts, phrase relationships are handled a bit differently for supplemental pages. He didn't reveal details.

Webmasters shouldn't be worried if they have pages in the supplemental index. Matt Cutts has hundreds of his own pages in the supplemental index.

Catalog pages and online store search result pages:

Google tries to avoid online store result pages in its own result pages. If an online store search result page looks like search results that are available anywhere else, then Google doesn't like the page. It's much better if it has unique content.
Category pages in online shops work better according to Matt Cutts. However, a product should only be listed in the best-applicable category instead of being listed in 30 different locations.

Matt Cutts recommended to analyze the web pages that currently have high rankings because webmasters can learn from them.