Is it suitable for large corporation to build multiple websites? And what are the pro's and the con's? Think of cost, application services, development, etc.
Here is my answer for that:
There are several versions of Magento. Magento Community, Magento Enterprise and Magento Go.
Cost wise, the community edition is the best but you lack the support. For a corporation, the Enterprise edition is the best with $1,000/month for a good support.
What differentiates Magento is its interoperability with various back office systems (natively or via other bridging tools). In addition, Magento is getting the defacto for corporate e-commerce as it scales up well (with extra cost for scalable license) and it is search engine friendly.
Other pros are related to development cost and graphical layout. It is one of the best within the upper end e-commerce packages.
Some of the Con's is the limited access to licensed developers (which is being solved right now by the new certificate system). The classes are free for a while during the beta stage.
Another risk arise from the fact that Magento depends on other tools for the connection with back-office inventory (SAP for example). There are various tools to connect but most of them are being developed out of the Magento Eco-System hence their maintenance is an issue.