How does Airdroid make money

I love airdroid but I'm wondering how such I well put together service could exist. Are you guys just really nice or is it one of those start-up stories where the business model comes after user base? Should I be concerned that I will some day need to pay / endure ads?

I would like to know that too, will it be free forever? It's just too good to be true

I would like to know that too, will it be free forever? It's just too good to be true

I would like to know that too, will it be free forever? It's just too good to be true

I would like to know that too, will it be free forever? It's just too good to be true