Google defines link spam as "creating links to or from a site primarily for the purpose of manipulating search rankings". The old warnings about directories, comments, press releases and widgets are now written policy:
| Practice named as link spam | Exception |
|---|---|
| Buying or selling links, including for free products | Qualified with sponsored or nofollow |
| Excessive link exchanges; automated link building | None |
| Optimized anchors in guest posts, advertorials, press releases | None |
| Low-quality directory and bookmark sites | None |
| Keyword-rich links in widgets or cross-site footers | None |
| Optimized links in forum posts or signatures | None |