The reason the first 100 can be tough is mostly due to that your a new channel with some or no experience regarding content.
Once you start uploading you first have to gain audience wich is the challenge as many other bigger channels already gain most of that audience, one you finally worked your way up to the 100 you have a base but then the real challenge begins. How do you keep those 100 alive and kicking and gain the other 900 to reach the 1K?
The more content you have the more people that should be able to find you is what everyone thinks wich in a way is true but quality also matters, scheduling uploads so people know what is to come, experiment and try out new things to reach additional audience and most important Networking! By gaining a network you spread the word as Person A sees your video and thinks: Hey! I need to tell this to B and B thinks: Hey! i need to show this to C and D and so the train starts to gain subs and views but now to keep them entertained the whole journey trough.
