One popular and simple way to use Arq is to back up to your Google Drive account. You get 15GB of storage for free. Larger storage options are very inexpensive -- for example, 1 terabyte of storage is only $9.99/month. The Google Drive for Work offering is $10/month per user and includes unlimited storage!
Another popular way to use Arq is to back up to Amazon's Glacier storage service. Ongoing storage cost in Glacier is 1 cent per GB per month. That's just $1/month for 100GB of data.
Alternatively, Arq can back up to any SFTP server. This is useful for example if you want to back up to a NAS on your network.
Arq will also back up to GreenQloud, DreamObjects, Google Cloud Storage, or any S3-compatible storage service.
No matter which destination you choose, your file data are encrypted before they leave your computer, so your backups are safe from prying eyes.
Next: Adding Your Backup Destination