When my parents bought an iMac in 2013, they opted not to buy an external drive for Time Machine. They never did buy a drive, but I configured Arq for them. When their internal drive failed three weeks ago, they thought they lost their 40GB of data, including critical and irreplaceable financial documents and spreadsheets. They had been skeptical of cloud storage despite my showing them their encrypted files in Google Drive, but that changed when I fully restored their files using Arq. Thanks to your app, the hardest part was safely transporting the iMac to/from an Apple Store for warranty replacement.
I myself have been using Arq since 2010, and fully restored 300GB from S3 in 2012 when my SSD corrupted and found my Time Machine was months behind.
There is no question: Arq is an absolute must.
We will be lifelong customers and advocates.