Google has discontinued its domain blocking tool (known as The Blocked Sites feature”) i
The tool would allow internet users could elect not to see results of say parked pages or content farm pages in their search results when logged into Google.
Google says users can still block particular sites from your search results, we recommend the Personal Blocklist Chrome extension from Google.
You may also download your existing blocked sites list as a text file.
So for parked pages, especially mini-sites it could mean a boost in traffic as a lot of domains that were automatically blocked by Google will no longer be blocked.
However you should keep in mind that Google’s Penguin updates have attempted to discount Exact Match Domains for sites without unique and valuable content