It's from Rendezvous in Memphis. Not the best barbeque in Memphis, but it's world-famous, and a good example of the style. It's impossible to find properly cooked Memphis style ribs outside of Memphis (you'll find it on menus, but it's always garbage). If you want a bbq sauce that's special and consistent, this works.
You are buying national brands. Try something a little more local
Bonus: You get to try something you've probably never done before
1 6oz can tomato paste
1 small can chipotle peppers in adobo sauce
1 onion
a few cloves garlic
salt, black pepper, some cayenne
1/3 cup of each:
white vinegar
apple cider vinegar
molasses
brown sugar
Throw it all in a blender or food processor. Taste and balance salt/sugar/sour (note it will get sweeter on cooking). Bring to a simmer on the range for 10 minutes. Done.