I want to know the answer to the following question:
What made Pacinotti's motor an important advancement?
All the background I'm provided with is that "In 1873, Gramme showed that his dynamo could be used as a motor, which he demonstrated to great effect at exhibitions in Vienna and Philadelphia by connecting two such DC motors at a distance of up to 2 km away from each other, one as a generator.". Is that enough to answer the question?