Place pork roast in a slow cooker. In a mixing bowl whisk together light-brown sugar, chili powder, paprika, onion powder, garlic powder, salt and pepper.
Add in chicken broth and tomato paste and whisk mixture until well blended. Pour chicken broth mixture over pork roast in slow cooker. Cover slow cooker with lid, cook on low heat 7 - 8 hours.
Remove roast from slow cooker, remove fat from roast and shred (I don't shred the pieces very small because it will kind of have a "mushy" texture if you over-shred it). Ladle out some of the fat (the shiny orange layer of liquid) from the top of the broth in the slow cooker and discard.
Return shredded roast to slow cooker and allow to rest on warm heat for 1 - 3 hours. Strain broth. Serve inside tacos, enchiladas or burritos or serve over nachos, salads or tostadas.