According to data from the Department of Transportation, 46,000 travelers were involuntarily bumped from flights in 2015.

On the flip side, there were 505,000 voluntarily bumped. That’s a huge difference.

The reason why is that many travelers don’t mind volunteering their seats to wait for the next flight out. In fact, some people will even book flights just so they can get bumped to earn extra cash for travel.

As we all know, the airlines have cut capacity, which means that most flights are operating with a full house. This increases the chances of getting bumped, especially on peak travel days like Monday, Friday, Sunday, and around the holidays.

Here’s how to get bumped:

1. Check flight loads
Most airlines will allow you to see your flight’s seating chart (go into your reservation online and click the “change/view seats” link). But it’s best to try booking a ticket (don’t purchase) on your particular flight. If they aren’t selling seats then they are full or oversold. You can also call the airline directly and ask the operator if the flight is oversold. Here’s a handy list of all the airline websites and their toll-free numbers.

2. Volunteer to get bumped
Airline reps love it when passengers volunteer to get bumped. When I’m playing the bumping game, I will usually check-in with an agent at the ticket desk to let them know. Then I will go to the gate and wait for an agent to arrive—usually an hour before departure. I then ask politely if they are oversold and if they need volunteers. If so, I ask to be included on the list. NOTE: Most of the time, agents won’t know if they need volunteers until midway through boarding so they will put you on a list and hold your boarding pass. Tip: Don’t keep bugging the agent…it will only tick them off and decrease your chances of getting the good stuff.

3. Wait close to the gate
Sometimes agents come to the gate late and just get on the PA and announce they are looking for volunteers. That is why you should be standing close to the desk so you can be one of the first people to jump in line if they ask.

4. Be sure to get on another flight
Before accepting a bump, first find out how much they are offering; domestically it’s usually around $400 and internationally it can be up to $1,350. Then find out when the next flight they can get you on is. If it’s an overnight bump, the airline should provide you with a hotel, transportation, meal vouchers and sometimes even a calling card, though not always.

5. Get a cash voucher not a flight
This is very important. Do not accept a roundtrip flight because they come with heavy restrictions and blackout dates. Plus, you won’t get frequent flier credit for your flight(s). Instead, ask for a cash voucher that’s usually valid for one year from the date of issue for that airline. Note: Some airlines (Ahem, Delta) will even offer you gift cards to stores like Good to know: If the airline involuntarily bumps you (meaning you didn’t volunteer to get bumped), be sure to ask for cash, not a voucher. This happened to my sister and her family when they were traveling from Miami to Barbados because they were the last to check in and they each received $1,350.

6. Be nice
It’s very important to be genuinely nice to the agent. I always try to make friends with them and will even bring them chocolates since most passengers treat them terribly.

7. Ask for a lounge pass, upgrade, hotel, and food
If the agent is struggling to find volunteers, the money usually goes up and so do the perks. I normally won’t change my plans for anything less than $500, even if it’s a short bump. But I will always see if they can bump me into first class on the next flight or give me a premium economy seat. Before I had credit cards that got me into the lounges, I would ask for a lounge pass as well. If you don’t have one, ask for lounge access and a meal voucher (usually $10-$15).

8. Do it all over again on the next flight
During busy periods, you can get bumped multiple times the same day or over a week. It’s a great way to get some serious money towards flights. Tip: When you get bumped, take a photo of the voucher and email it to yourself so you don’t lose it. Also, set reminders as to when they expire so you don’t lose out on your hard earned bump.

9. Don’t check luggage
You will have a much greater chance of getting bumped if you don’t have checked luggage since it’s a pain and very time consuming for the airlines to find your bag in the cargo hold.

Good to know: If you choose to volunteer and they don’t need you (they let you know at the last minute), you may lose your overhead luggage space and sometimes agents could give away your seat and you might get stuck with a middle. Ouch!