You might have heard of some trick that you can use to land a free upgrade to business class. They are all over the internet. And sure, in some select cases, these tricks might have actually worked. But they are far away from a guarantee that you will really get that nice seat in the front of the aircraft. Even if a flight is overbooked - the main reason why airlines give away free upgrades - there are often guidelines that decide how gets them. Often, customers with costly economy class tickets or frequent flyer status will be the ones to benefit. A good (even if not wholly free) option is upgrading with vouchers or miles and points.