Conversations relating to the topic usually resemble the following:
What is the per user cost of a SugarCRM license?
Can one resell a customized version of SugarCRM?
Is it possible to provide SugarCRM hosting services?
One of the first important points to bear in mind regarding these types of questions is that the answer can vary depending on the edition of SugarCRM in question. This is especially true for the question of licensing costs, as Community Edition is completely free, while Professional, Corporate, Enterprise and Ultimate all require payment on a per user, per month basis.
More importantly, many of these conversations tend to only revolve around equating open source to FREE (as in costs, not liberty). As discussed, it is true for Community Edition, but not for the other editions of SugarCRM -- although they too are open source.
It is also equally important to note that open source is a programming philosophy that incorporates both the idea of making software available at no cost, as well as free to be shared. This latter part has significant ramifications on the answers to questions such as those posed earlier in this post and in turn, business models one might be considering that involve SugarCRM.
Perhaps the most overlooked matter of importance is the issue of whether or not one can customize and then resell SugarCRM. Usually this comes up within the context of the idea of creating a vertical version of SugarCRM.
Not to get too sidetracked, but vertical refers to a version of a product that is highly tailored to fit the needs of a specific industry, such as real estate, healthcare, automobile dealerships, etc. A default SugarCRM install is said to be horizontal, as it is not specifically designed for any given industry, although its flexibility makes it a more than adequate starting point for many vertical solutions.