The first way, the most common, is to sell Azure migrate server by server or workload by workload to an IT department. The problem with this approach is that you have to sell again and again every migration project. Sales cost are high and the customer will invite competitors to keep your offerings sharp. Result is the margin on your Azure business is low and it is hard for you to sell added value services and with that the opportunity to tightening the relationship with your customer.
The second way is to challenge the customer to make a strategic decision to migrate their entire IT landscape or big parts of it to Microsoft’s Azure. This requires to convince the entire Decision Making Unit of the customer and not just from the IT manager.
The big advantage of this approach is that you only have to sell this once, if successful you become the trusted partner, your customer relationship will become more sustainable and because of that you can make higher margins by selling added value services.