Designers don't send free clothing to the general public. However, fashion designers may send a person free clothes if she is a model or celebrity.
It is common in the fashion industry for young models to receive in-trade compensation instead of money. In-trade refers to the model trading her services by walking down a runway, or posing in a magazine editorial, for free designer clothing pieces. Up-and-coming designers often compensate models with free clothing, but established designers do this as well. In exchange for exposure to a wide audience, designers lend or give clothing to celebrities to wear at red carpet and other events.