Growth hacking is a marketing technique used by startups that focuses on creativity, data analysis, and social metrics to gain customers and exposure. It involves rapidly testing ideas through prototypes and measuring results to iterate quickly. Some key aspects of growth hacking include having an awesome product, thinking creatively, understanding viral growth loops, seeking major changes not just improvements, and being prepared to fail many times. Successful growth hacking examples include LinkedIn allowing public profiles to boost search engine results, YouTube making it easy to embed videos, and Airbnb contacting people with listings on Craigslist. Qualities of a good growth hacker include problem-solving skills, ambition, understanding users, discipline, coding ability, and bravery in testing bold ideas.