Airberlin has launched a promotion to buy Topbonus miles at up to 50% bonus until October 2, 2016.
You can purchase up to 50,000 miles during a calendar year and the maximum bonus under this offer applies when 30,000 is purchased.
You can access this offer on Airberlin’s website here.
Here’s the bonus table:
Here’s the price:
You can purchase Topbonus miles at 1.33 euro cents each.
This reminds me that I would need to find use for the 70K+ miles that I have had sitting on my account already for a while.