My client has four web sites that have many top 3 positions on Google for hard to rank keywords like “plastic parts”
They are going ahead with this against my advice. I think they will loose most of their top positions. they claim otherwise.
Anyone know anything about this?
Thanks, surfwiz
Know anything? No, I’m afraid not. 
But my guess is that you’re right. I had a single site covering two different topics, which I eventually split into two sites, each with a new domain name. There has been an improvement in ranking and slight increase in traffic since the split. These are very small sites, though, and my experience hardly constitutes firm proof of anything.