These days, there’s no need to spend hours combing through different travel sites in search of cheap flight deals. Just head over to Jack’s Flight Club, sign up for a free membership, and wait for flight deal alerts featuring the best deals, hidden discounts, error fares, and really cheap flights.In addition to the free membership option, Jack’s Flight Club also offers a premium membership that can score you even more flight deals every week. But what’s the difference between the free version and Jack’s premium service?