People can’t always give you what you want, but they are often willing to give what they can. For instance, a customer might not be interested or in a position to buy your product, but if you’re on good terms with her, you might be able to get critical feedback while putting the product in her hands for a little while and letting her test drive it. This might open the door for a future sale. If you’re looking for a job, asking to be hired might get you a brick wall, especially if she’s not looking. A sincere request for a resume or portfolio review however, will get you two things: your work in front of someone who in the future might be willing to hire you and professional feedback on how to make your portfolio better for the next person.