If you want to gain an advantage in diablo 3 then you are going to need to use some D3 Macros. Macros in diablo 3 are different than other online games because diablo 3 has no real legit macros. Other games by blizzard such as world of warcraft allow players to use some minor macros to help them complete some small mundane actions in the game, but with diablo 3 that is no the case. Diablo 3 macros are going to be only non legit things in the game.
An example of a diablo 3 macro would be something that would only farm a specific spot in the game. Now here is how you would actually make a macro that does something like that. First of all you need to download a macro creating program. Some good programs would be autoit, macroexpress, or actools. After you have the macro downloaded then start the program of course. The macros all come with easy directions on how to use them, the best of these would have to be autoit since it allows you to easily change things for the macro, and has a great tutorial.
After you have the macro program installed then go and take your character to where you want to farm. Lets say you want to just farm a specific dungeon. Well first of all have your macro create a game and have it always add a higher number to the end of it so lets say you have it type awesomepossum1 then the next game the macro would create would be called awesomepossum2. After that the macro will create the game and enter the world. You want to be sure to give the macro tons of time for things to load. So normally if something takes 1 minute to load give 2 minutes for loading. Once you are in the game then you want to open up your spell book and teleport to the area in the game you are after. Once you are there you can select the macro to wander around the game world. Its pretty easy to have the macro just move around until it finds a mob once it does the macro will stop traveling and try to kill the mob and loot any high items you set the macro to loot.
Finally you want to let the macro run around for lets say 15 minutes in the game. After that time the macro will log out and create a new game. This macro you have to know is very simple. Its not like a bot which actually thinks for all the things it does in the game. Bots are far more advanced but with a bot comes the risk of being banned as well. This is why diablo 3 macros are so big. While they might not be amazing they will help keep your account from being banned.