I'm not a domainer, i'm an end user. From my point of view if I'm buying a domain it would be easier for me to see its potential if it had a mini site with 5-10 pages compared to a holding page or parking page. That way it would get indexed by goog and if its an exact match domain, it would potentially have a good ranking. This will create more interest in the domain and a possible higher sale price for you sellers. But I almost always see domains parked, totally blank or with a single page with no keyword related content. Why don't domainers put up minisites?