Thanks to ancillary fees for baggage and other items, the way airlines earn money these days is completely different than it was just five years ago. Reuters
Passengers arriving on a delayed flight wait for luggage (Reuters/Jacob Silberberg)

Around and around the baggage carousel goes with your luggage nowhere in sight. Sadly, this is a familiar problem for many of us, and we're not alone. 29.4 million pieces of luggage were mishandled in 2010, according to a SITA, Specialist in Air Transport and IT Communications, 2011 Baggage Report.

The report includes those bags lost, delayed, or damaged. SITA found on average half of those bags lost were returned to owners with 2 days. But what about the other half?

Lost luggage can leave passengers wondering how the airline could have misplaced their bags and how to avoid it. Here are SITA's most common reasons for lost luggage.

1. Transfer

51% of lost luggage is due to transfer related incidents. This typically happens due to unknown tags, which are often caused by damaged routing tags. This stops luggage from automatically being moved to a destination. Agents then have to sort luggage by hand, causing delay.

2. Failure to Load

There are many reasons why a bag can fail to be loaded in the original departure location. Quick tip: Self-service kiosks lead to a greater risk of your bag being left behind. Go directly to the counter to have an attendant process the bags.

3. Ticketing Error

Oftentimes bags can be entered with the wrong airport code by the attendant. Double check the baggage code to make sure the attendant properly labeled the code, or else passenger and bag could be headed in opposite directions.

4. Weather

Weather often plays a crucial role in whether bags will make it to their destination on time or not. The Northern Hemisphere was hit hard in December and January by snow and ice causing these months to be some of the worst months for luggage. Iceland's Eyjafjallajökull volcano eruption caused over a 100,000 flight cancellations, which resulted in a mass of delayed or lost luggage as well.

5. Loading/ Offloading Error

Errors can occur in the process of loading or offloading of bags. One problem is confusion on the tarmac. Luggage can usually be boarded up to ten minutes prior to departure. However, often there is a lack of coordination between planes coming in and those loading luggage.

How to avoid the hassle of lost luggage:

1. Make Your Bag Stand Out

Putting bright color stripes or other accents allows passengers to be more descriptive in filing a report on lost luggage. The zebra stripped luggage bags may look silly, but it's much easier to find than the traditional black suitcase.

2. Identification Cards and Itinerary

Put a copy of the flight itinerary in front or in an easy to access pocket along with an identification card displaying your name, address, and phone number in several locations.

3. Secure Loose Ends on Bag

Taking off straps or making sure nothing is dangling off the bag reduces the chances of the bag becoming stuck along the belts used for loading and unloading.

4. If Your Bag is Lost Make Sure to get Reimbursed

If you bought flight insurance, make sure file a report to get reimbursed. Also, a new law enacted in late August by the US Department of Transportation requires a refund of any baggage fee to be given to passengers whose luggage is lost.