Those of you unfamiliar with the U.S. Mints free coin delivery program might be missing out on an opportunity to earn credit card miles to pay for travel expenses.There are several Websites that share information about earning frequent flyer miles. One informative Website is www.flyertalk.com.The Mint offers Presidential dollar coins and Native American dollar coins in 25-coin rolls packaged in quantities of 10 rolls per box with a face value of $250. Customers can order a maximum of two boxes, for a total of 500 Native American dollar coins. The Mint pays the shipping and handling fees on orders delivered via standard shipping methods.Pat McAfee, director of the Mints Office of Dollar Coin programs, told me the vending industry has made good use of the free shipping program, which has been in effect since June of 2008.The Mints concerns about the programThe tactic of ordering large quantities of dollar coins to earn travel miles has become so popular that the Mint is trying to crack down on letting people benefit from the free shipping just to rack up miles. In the meantime, dollar coin availability from the Mint is at an all time low.Dont confuse the current shortage of dollar coins with the Mints efforts to crack down on people ordering coins to rack up miles.You may have read recently that credit card companies are going to stop awarding miles on dollar coin purchases.In his conversation with me, McAfee confirmed that the Mint is working with credit card companies to try to stop people from racking up free miles for dollar coin purchases. At this date, nothings been finalized.He also told me that the Mint wants to continue offering free shipping of dollar coins to vending operators.As far as the dollar coin supply is concerned, McAfee said he expects dollar coins to be available in two weeks. He noted that inventories do get low periodically.For information about the program, go to www.usmint.gov.