Is there such a thing as "free lunch"? When is "free lunch" truly free?
Assuming that we're talking about a literal lunch, the answer is never. A lunch has value: someone had to collect the raw ingredients, someone had to put them together, someone had to serve it to you, someone had to pay property taxes and upkeep on the restaurant, and so on.
With lunch, someone gains only as a result of someone losing. With a business lunch, the salesperson or the interviewer pays for your free lunch. With a soup kitchen, the charity or local government pays for the lunch. The charity gets its resources from charitable donors, while the local government gets its resources from local residents. The same applies to any item that has value: no one acquires it without incurring a cost.
Today I want to tell you about a way to get free lunch. In fact, I'll make it as simple as possible: I'll give you step-by-step instructions that almost anyone will be able to follow to fruition.
1) Get a credit card that offers rewards;
2) Visit the US Mint and find the "$1 Coin Direct Ship" section;
3) Order online as many coins as you can with your rewards-bearing credit card;
4) Receive these coins in the mail;
5) Deposit the coins in your bank and pay your credit card bill;
6) Go to step 2.
I did one iteration of this, and I come with photos. Here's the box I received in the mail:

Here's one sub-box with 250 $1-coins:

With my credit card, I made $33.33 in rewards for doing essentially no work, and I can repeat this ad infinitum. This can buy a hefty lunch!
Is it a win-win? Who paid for my thirty-three-dollar lunch? I expect to see a correct answer in the comments.