With refrigerator liners, like most other consumer products, you tend to get what you pay for. Higher-end refrigerator models have thicker liners that are more resistant to cracking. Conversely, manufacturers save a few pennies by stretching liners quite thin during installation, lowering the final price but creating a higher possibility of cracking. If you're concerned about the possibility of a cracked liner, spend more on your refrigerator.
The good news is that a single small crack won't have much of a detrimental effect on your refrigerator's performance. In other words, it won't send your electric bill shooting through the roof or leave you with a constantly running compressor. The problem becomes slightly more pronounced if the crack develops into a longer break or manifests itself in multiple places. The more tears in the material, the better chance it will run at less-than-optimal performance.
Another reason that refrigerators are designed with a one-piece plastic liner is that food spills are contained and can be easily cleaned up. Imagine the possibilities if you accidentally overturned a gallon of buttermilk and it all ended up inside the compressor. Consider the same scenario with a dozen dropped eggs or a mishandled jar of syrup. The refrigerator's mechanical cooling system components work much better in the absence of food product exposure.
While you can call a professional to tend to liner cracks that develop, there is a simple way to make the repair yourself, according to HomePartsAndRepair.com. Simply drill a 1/8-inch hole at either end of the crack, which stops it from spreading. Next, use either a small amount of silicone or some liner repair tape to finish the job. There's a good chance the manufacturer of your refrigerator can provide a crack repair kit if you contact the company.