Al: I think he was referring to Overloading of the server(s)

If that is what you are saying TheReason. I feel it can hurt your business as people will say "My site takes a long time to load, do not host with XYZ etc.." also it will put stress on you as a business owner. If you have 3k sites on one server I would consider that overloading. On the other hand if you have 3k domains that are pointing away from your server you should be fine etc.. ie. ppc pages