Older, pre-industrial "capitalism", was based on land ownership and earning rent money from it (eg by leasing it to farmers, etc).
Modern capitalism was/is supposed to be based on investment - ownership of stocks and bonds. Supposed (look at the subprime crisis and the dynamics that led to it).
IMO, the emerging capitalism will be based on the residual value and rent income from intellectual products. That is why, in spite of the issues of piracy made more crucial in recent years due to the emergence of new electronic media, the US and to some extent the EU are placing emphasis on protection of copyright both domestically (eg the US Millenium Act) as well as in international agreements and negotiations (WTO or bilateral).