Essentially, the 8 means 'good' or 'beneficial'. This is a very broad value term. 'This is a good thing.'
 
As in many languages the 'adjective' usually comes after the noun, thus 68 (a good result).
 
When 'good' is almost the key factor the 8 can come first, as in 89 (good time or fast).
 

• 68 good result
• 38 an effective person
• 28 a good method or system
• 718 this is a good situation
• 282 flexibility ('good change of change')
• 86 purpose
• 89 fast
• 83 pleasurable
• 82 benefits