Selling isn’t optional. Regardless of the type of company, industry in which it’s active, selling is always an integral part of running a business.
Some people seem to excel at selling, whereas to others, selling doesn’t come as natural (straight away).
References, on the other hand, aren’t optional either. Whether it’s a photographer’s portfolio, a corporate company’s case studies, a restaurant’s reviews…
If selling isn’t a particular entrepreneur (and their company’s) forte, the importance of the references increases. A portfolio that the creator can take genuine pride in is bound to ooze out passion. When your heart is all the way in it, it rubs off, selling your work for you almost automatically.
Selling and (the ability to show) references aren’t optional. If one doesn’t come naturally, compensate with the other.