I do not know who told you that, but MS are pretty clear on what you can and cannot: Internal use licenses are for use in a production environment for genera

I do not know who told you that, but MS are pretty clear on what you can and cannot: Internal use licenses are for use in a production environment for general internal business purposes and not for any type of commercial purpose. For example, installing the Windows Server operating system and Microsoft Exchange Server to set up an email system that you can use to send business-related email is acceptable. However, production use for external commercial purposes, such as hosting a commercial website, is outside the scope of these rights. Customer demonstration licenses can be used for demonstration purposes only by partners. Sales and marketing employees of the organization can use this software to showcase products to your customers, but demonstration products cannot be installed on customer hardware or infrastructure and must be used with partner supervision. Internal-training licenses can be used for training internal employees only. These licenses cannot be used for customer training or for any commercial purpose. MSDN subscriptions allow designated employees of your organization to use the available software for the design, development, testing, and demonstration phases of application development.