I'm not exactly sure how many games out there use random boxes in their item mall or item systems, but the two that I do play that have these features are Atlantica Online and Lunia. Random boxes are exactly what they say they are. You have a chance to get 1 of several items from the box but you don't get to choose which one. Sometimes you are given 1 that you can't even use. The following is my rant about it.

1) Its random!

I spend hours or days trying to get this rare box. The result? I get a piece of crap worth less than what the box could have sold for if I didn't open it. Chances are its also useless to you because it wasn't what you were looking for. In fact, its 1 of the 20 other items in the box that you didn't need and not 1 of the 3 you might need. Or worse yet, it might be an item that you can't even use. Its just a scheme to drive up rarity on items that aren't even suppose to be rare. On top of that the game developers like to keep it mysterious so you don't exactly know what you're going to get until you open it. Its just an incentive to get more boxes and open more of them. Either that or you just save your money and just pay like 20x the value of the box for the 1 specific item you need off another player to save yourself time and effort.

2) Its not completely random!

As random as these boxes are, each item inside might have a different rate to obtain it. There might be 20 items in that box but the rates for each one are different. That one that looks good might have a 1% rate while the piece of trash has a 90% drop rate on it so chances are you're going to get the piece of trash. But that the same time, one isn't really better than the other except for visual preferences. To mess with you some more, they make some boxes random and some allow you to choose. This has to be the most annoying thing ever. You KNOW they make most of the boxes random and on purpose they show you that not everything has to be random. Its fixed against the player on purpose.

3) I can't farm it!

One of the things important in MMOs is the ability to get the items you need. Random boxes prevent you from doing so and forces you to gamble for what you need and pray you get it. On top of that, if the item has a low rate, it might be nearly impossible to obtain the item. "Farming" might lower the price of items, but its essential to MMOs to deflate prices over time. Otherwise the price of everything just goes up endlessly and unless you're at the top, you can't benefit from it.

4) I can't use this crap!

One of the most annoying things about random boxes is well, random. If your character is 1 type and there are 8 other character types then it will be a pain to obtain the item that you can use. It also drives up prices greatly for the character types that are used more. The army of warriors who may be crappier than say the army of mages have to pay 3x more for their items regardless because there's just too many of them. The boxes give "equal" chances to everyone but its not really equal because there's so many of 1 type of player that the prices go through the roof. They can't farm more of that item to lower the prices because the randomness will prevent it from happening and might cause an oversupply of one of the other types of items anyways. Your only hope is to pray that you get 1 piece that is more than the 1 you're looking for and trade it. Either that or keep gambling on the super low rates.

5) I got the same thing twice!

Another problem with having the random items is that you'll most likely get the same item twice. When you have a set of say 6 pieces of equipment, you're going to need a lot of luck to get taht 7th piece to complete the set. This is pointless and might force you to go through 10 or more of that box to obtain that 1 specific piece you need. At the same time, there's also a chance that you won't get that item until the 100th box. Rather than put up with all this crap you could just farm money and buy it off another player. Plenty of games feature rare sets of equipment or collectible sets that are hard to get. Putting these random boxes in their place make it even harder and more annoying to obtain. There's a limit to how much crap people are willing to put up with and this greatly stretches it.

6) Gambling model

I know more than the 2 games listed above are basically fixing the odds against you in the form of gambling. Players have to spend huge amounts of money to gamble on items they need and hope they get it. The publishers and developers can modify and fix the odds against you at any time even for short periods of time without you even realizing it. Gambling is encouraged by all and suppose to be appreciated by all. But as people know, gambling are shams that only benefit the person who is providing the gambling service. It is always fixed so that they will end up on top. And to those publishers and developers who do this on their item mall, shame on you for encouraging this kind of behavior. Do you even know why the world is in a financial crisis in the first place?