And crap to put
out 
If you are dieting correctly, you should be going to the bathroom at LEAST once per day if not more, and I don't mean to take a piss. This goes double for all the hardgainers we have here.
I'm a mesomorph (normal build), 6"1' at 149 lbs. I should take in at least 3500 calories per day to gain significant mass. It's hard to work off of numbers alone, so I'll give some food examples to illustrate just how much this is. This isn't what I eat. But hopefully, most of you have eaten these at one point in your lives and have some idea how much food this is.
KFC: ~13 extra crunchy thighs (the most fatty piece they sell)
Pizza Hut: 2 large pizzas
Carl's Jr: 3.5 Bacon Cheddar 6 Dollar Burgers
Subway/Quiznos: 3.5 Foot-long subs
Chipotle: 2 burritos
Keep in mind that most of these foods are extremely high in fat and because of that, you don't need to eat very much to have a ton of calories. Eating at home, this equates to about
3 lbs of steak or 5 lbs of chicken in terms of protein.
This is for me, personally.
Any hardgainer needs much, much more. I literally cannot overemphasize the importance of diet.