i thought about this before (giving away small amounts to friends to let them learn about bitcoin) but in the end i decided that letting them learn about how to use bitcoin through testnet is a lot better than through mainnet.
using testnet they won't have to worry about money so they won't get greedy to hold it and never use those coins to learn anything. also if they make a mistake and lose it they are still losing a worthless coin (tBTC has no value). on top of all that you can give them any amount not just a small one and they won't have to deal with possible high fees if the time they were using bitcoin coincided with a network congestion.