Well, a "business model" to sell companies would be something like an incubator...a company that continuously created new companies and sold them off. Of course, since the talent that was able to execute on these ideas is going to be the most useful asset that these spinoff companies have, eventually your incubator will look more and more like an investment firm. If you think about it, investors are in the business of (helping to) build products to sell to other companies (or the public).