I was sitting on the airplane a few months ago and spoke with a
gentleman who said he lived in San Francisco and started up a
marketing company that would "start up about 12 companies a year [one
a month], and then on average sell off one of them."  That would be
their revenue for the year.  They'd incorporate, set up the market
research and the business plan, get the right people on board, let it
run for a few months and then sell it off.

Most of his companies were Web-based, but it sounded like his company
was quite versatile as it dealt with patents for innovative medical
devices which detected SIDS and so forth.

My question is what do you call the industry that this type of company
is in?  It's like a for-profit entrepreneurial think tank.

Moreover, specifically what I'm asking you to do for me is to find a
list of companies that start up innovative companies for a living and
then sell them off.  He told me that there were quite a few companies
like that in the Bay Area (CA) but I'm having a hard time finding
anything.  If you can help I'd love it!