Benefits of not spilling seed as a way of life         
Better physical health, more strength, better sight, stronger hair and teeth, better breath
Prevents sadness, depression, anger, nervousness.            
Better mental health, stronger mind
Less embarrassments, stronger self esteem.
More confidence.        
Better control over one's inclinations, better self-mastery          
Better connection to spirituality.           
Easier time finding spouse       
Better marriage           
Easier livelihood         
Better overall health (health is not only physical , one can have a healthy marriage or finances).         
Merits having holy children who are also careful with this            
Better Shabbat experience  
Attains certain amount of might         
Saved from enemies, it is a protection against the evil eye, gives one a distance from wicked people          
Protection while traveling   
Merits a constant state of happiness         
Merits delight and pleasure in the service of G-d. 

From Holy Nation ebook available for download on Guard Your Eyes. 

There are not that many actions that can give you these incredible rewards! One might say these are a mans ultimate goals in life. 

You want to escape from the hardships of life?
Escape into Torah! 

"Even so did the Holy One, blessed be He, speak unto Israel: ‘My children! I created the Evil Desire, but I [also] created the Torah, as its antidote; if you occupy yourselves with the Torah, you will not be delivered into his hand."