Some home or car insurance companies offer miles to people who request a free rate quote.
For example, a quote on auto, home or renters insurance policies at Liberty Mutual Insurance will earn you 500 American Airlines or Delta Air Lines miles. An auto quote at Sentry Insurance nets 1,500 Delta miles.
At 21st Century Insurance, you'll get 300 Delta Air Lines miles and 200 US Airways miles for an auto insurance quote. If you actually purchase a policy with 21st Century Insurance, you get an additional 2,000 miles on US Airways.