The ability to segment our lists is great for targeting prospects who are most likely going to be interested in what you offer! We can't use it all of course but that makes sense since there isn't much benefit if I could do an entire list at once instead of just segments. It only takes about 10 minutes per profile/list to set up so not too bad - maybe more with larger profiles or lots of different accounts (we've got several). You must know how many people will actually see your ad when running campaigns which means having good sales numbers ahead of time really helps here because otherwise they may think "oh well no one saw my post" even though everyone was targeted correctly. Also some smaller businesses won't like this method due to lack of control over advertising spending / budgets etc; however large companies should find value very quickly given enough volume being sold across multiple platforms simultaneously using.