Spend your own money to build your core competencies. Use partner resources to shore up your weaknesses. If you use a partner to build your core strengths, they will learn from you. The strengths you bring to the partnership will diminish in value to them. As your value decreases you become weaker. You can even lose control over core elements of your business. If you limit your partner’s contributions to building up your weaknesses, it can only make you stronger. You will have little they can possess away from you. If you proceed in this manner, you’re unlikely to cede control over core elements of your business.