Avios has an interesting game on facebook called Avios Suitcase. You answer questions or share content on your twitter and facebook and in return you earn Avios. It is a fun game and definitely easy Avios to earn.
I have earned approximately 500 Avios so far from this game and though it is not a game changer it helps build your Avios. As Tesco says ” Every little helps” :)!
You can find more details about it here.
Remember that if you don’t want to share content and “spam” your friends on Facebook, you can always share it only with yourself from the settings. You will also need to have an account with Avios.com in order to be able to deposit your Avios. Once your Avios are deposited there you can transfer them to BA.com via combine Avios, which is instantaneous.
Happy Travels 🙂