As Drupal 7 reaches it's end-of-life, I expect that Backdrop use will surge. Many of the small to mid-sized websites that are built on Drupal 7 will not find Drupal 8 to be appropriate for their needs, and with the easy transition to Backdrop they will find the critical features they need along with a bunch of usability improvements and new features they're going to love.

Backdrop is a great alternative to Drupal – if you are evaluating options for your Drupal 7 site, definitely include Backdrop in the mix.