I love that I can search any of my customers and know exactly what they are buying of the products we represent. I feel as though Tableau does the hard work for me, and it is impossible not to be able to set a high standard with customer relationships on the first meeting when you have so much information about them at your finger tips.
I dislike that it takes about 4 months to see an update in a customer's purchase history; I would love if it were only a few weeks from the date of sale, so we as a company can confirm with data that they bought an item as opposed to holding on to their word for it and find out months later they might not have started buying the product just yet/there were issues.
It gives you full access to operators in regards to their usage of your products and who they are buying from. It makes selling so simple as you do not have to spend much time doing research with all of the information being in one place -- making it easier to work with accounts that are already loyal users buy other products of yours or notice they might benefit from alternatives products based on how much they are currently using.
I go in to accounts fully confident in know who they buy from, what they buy, and how much per quarter so there is no wasting time in presenting items they already use or might not be interested.