The ability to target users by interest, location or device is very helpful when it comes time to deliver ads in your campaigns. I like that you can create custom audiences as well which saves me from having to use an existing one if there isn't anything available yet. It's easy enough to figure out how things work but some of their documentation could be better (esp. around advanced features). We are able to reach people who may not have visited our website otherwise so they get more exposure without us spending additional money per impression/viewer etc. This has helped improve CTRs across all ad creatives we run so far. Also been beneficial because now we don’t need to waste any budget advertising where no viewers will see them!