DNA is actually a very efficient storage method, but it is not very practical right now. It costs thousands of dollars to encode a book to DNA, but the cost is expected to gradually fall as the years go by. It is expected that by the next decade, DNA storage will become useful and economically feasible.
Harvard researchers pursued this promising idea because it has been discovered that as little as four grams of DNA can store data that humans produce in one year. That means that there will be lot less storage space when compared to the flash drives and hard drives that are commonplace storage devices at the moment.
