darkyl - 9:27 am on Mar 20, 2009 (gmt 0)

If you were running a search engine, would you want your pages filled with results coming from the same company, offering the same content/products, even if on different domains?
If it works today it doesn't mean it's a good idea.
Google changes often and it's pretty clear they're always testing new ways to "differentiate" serps.

I wouldn't be surprised if the good results achieved with this method would be gone tomorrow.