Why go with a paid analytics solution?
When you pay for a product, it ensures that you are not the product. Free analytics solutions use your own data against you within advertisement networks. They use your data to increase the cost of paid ads, they sell your data to other companies, and make your data available to people willing to pay for it, including your possible competitors.
Many of your users also view free analytics solutions as harmful and will employ special blocking software to prevent them from being tracked.