Age verification systems like AgeCheck  compare a customers data against large databases to attempt to confirm that they are over a certain age. If an AVS is unable to confirm using a database, the next step will be to request an ID which an AI will attempt to read and verify.  If this also fails, then a human will be called in to attempt to complete verification. These systems provide a means for a store to better filter out underage customers without the store having to directly touch or store private/sensitive information; with some caveats.

Pros:

• Relatively Inexpensive
• Used extensively for online sale of nicotine products and pornography
• Avoids shops having to collect and handle more sensitive personal information than they already do

Cons:

• Slows down the checkout process 
• Exposes shops to additional risk. If a customer lies on an age gate that is their fault; if a shop fails to correctly verify age with an AVS this is the shop's fault.
• A minority of customers may strongly oppose sharing their IDs even with a professional 3rd party

Unknown:

• Will an AVS system be stable during a drop with hundreds of people?
• How will customers react to slower checkouts?
• Can customer tagging be used to make AVS only required one time per new customer instead of at every checkout?