I came across this site where people can roll the dice, earn free bitcoins and also multiply them. How legit are these sites and how to use them effectively?
If you are talking about freebitco.in its pretty legit and been running for quite some years now, they also have some cool way to earn bitcoin via web (but its only satoshi and a waste of time if i will use it).
The effectiveness to earn bitcoin via faucet is not advisable but can give you a good amount if you continue to use it for years.
Some site are annoying and full of ads (which i hate), maybe try it for a couple of day or weeks and see if the result suits your taste.