Is it free to mint Asimi Tokens?

Essentially yes. There is no Asimi cost to minting; simply if you own Asimi tokens, you can get access to the Ad Minter to mint new Asimi tokens.  Asimi Minters are qualified to mint ads based on their Asimi ownership. 

Asimi minting Fee: To get paid automatically to your chosen wallet, you will be required to pay the small Waves transaction fee of 0.001 WAVES required by the Waves Blockchain.