I like that it's easy for me as an individual user, but also has advanced features such as creating custom campaigns or advertising groups which is great if you have multiple people using your account! It can be difficult at times when trying to figure out what exactly we are doing wrong in our ads so that they perform better (or worse).
The reporting system could use some work too - sometimes there isn't enough detail given about how well each ad performed within certain timeframes. If someone wants help setting up their campaign/ads then this service will do just fine. We've been able to get more traffic from social media sites compared to other companies who charge us per click whereas here its free.