Let us say you want to start 100 different types of online businesses (eg. social networking site, video site, gaming). Would it be better to start 1) 100 different separate sites with 100 different domains. ? OR 2) Portal (all-on-one with only 1 domain) ? Each new type of business will be added as a sub-folder or subdomain for eg. www.domain.com/sns , www.domain.com/gaming This will be like a Yahoo or Google where all members will have 1 login account and they can access all other services/ features offered in the community. New featured can be added easily and all members will have access to new services. Thanks