text: It depends on the oil. The big question is
  
  “how long do you want a diffuser to last?”
  
  If it lasts for 12 months, it’s basically not working and you don’t have a business. I’d suggest 6-12 weeks is reasonable for a small diffuser.
  
  Once you know how long you want your diffusers to last, you can start developing (or choosing) fragrances to hit that timeframe.
  
  We are launching diffuser recipes in the next few weeks with a target median diffusion time of 8 weeks (I think). So, we will be able to tell you exactly which fragrances will diffuse and at what rate.
  
  In my opinion - and it is just an opinion - a 100ml - 150ml diffuser should not last more than 10-12 weeks. If you’ve got a diffuser that’s still half full after 6 months….it’s not really diffusing, and even if it is, you don’t have a business.