"Today the customer service is better than it was three years ago."
Translation:Heute ist der Kundenservice besser als er es vor drei Jahren war.
'er' refers to the Kundenservice, 'es' to the previous being better or worse. to be, to like, to enjoy etc. always need something you are or like or enjoy and so on. Since this construction uses a subordinate clause and your something is part of the main clause, you need to fill that gap, hence you use es and it. You wouldn't need that if you said: Heute ist der Kundenservice besser als vor drei Jahren – Today the customer service is better than three years ago. I wrote some more about that here: http://duolingo.com/#/comment/204490
There should be a comma between 'besser' and 'als', since they're seperat clauses, as mentioned above.
It's been a long time since I actually had to do with this kind of grammar, but that's what makes duolingo so much fun for me. A little research suggested the adverbial clause and to me, it makes sense. I can't say anything about the english grammar, but in German it's purely comperative. Today the customer service is better fullstop. It's better than what..? It's better than it was three years ago. This only serves the purpose to define what it exceeds in quality. E.g.: Oh, this room is so much better. - Huh, better than what? - Better than our last hotel room of course, [don't you remember the broken shutters?] Contracting these would say: Oh, this room is so much better than the last one was. Hope that makes it a little less complicated for you.
I agree, it is interesting to "discover" these grammatical and idiomatic structures. German grammar is especially intriguing--it is very complicated and also very logical--much more s on both counts, I think, than English. That is partly why I am baffled when something like this seems odd to me. Your explanations help enormously. Thank you again!
I am a user of your service and firstly I think it is a great. It truly is a tool to bring people of different language together and to expand communication between people. I believe that Duolingo should expand to include Norwegian to the lesson plans. This language is often universal in my personal experience in traveling to Scandinavian countries. Please consider including Norwegian to your lesson plans.