It sounds a little outrageous, but they're offering a buy one get TWO free deal! (How that even makes sense... I don't know, but it's definitely good in my books!)
To give you a little more detail, with every £20 purchase, they will give you a free full size bottle of both the Volume Advance Shampoo and the Volume Advance Conditioner. What's more, they are also offering free delivery! Just enter the code 'VOLUME' at checkout. The offer starts tomorrow, while stocks last. Check out their website for more info.
The only Ojon product I've tried to date is their Damage Reverse Restorative Hair Serum (thanks to Glossybox!).