When buying transfers you are buying outbound dialed calls that are live ready to buy consumers in real time. The consumer has opted in through your advertising set up. When buying those transfers it is very important to make sure the Publisher (Seller) has all the things to be compliant w CMS, (In the Insurance Vertical for Transfers) and of course following TCPA compliance. You will make sure they have Jornaya or Trusted Form or both (both is optional to the publisher) When buying inbounds, you are buying inbound calls that are consumer initiated, therefore you will not have the compliance details to be concerned with. However there are many things to learn about the inbound, such as their advertising mix, are they generated for TV, or Social Media Search. There are many ways that an inbound call can be generated. There is industry jargon to learn, like Dynamic, Static, RTB (real time bid) etc. there is much to learn in the inbound process. I hope this helps! :)