The comic was on a long hiatus while Hussie was making Cascade.
When it was finished he uploaded it to Newgrounds to avoid having his site crashed from everyone rushing to watch it. Then... Newgrounds crashed from everyone rushing to watch it.
Then he uploaded it to Megaupload instead, which promptly went down as well. As did multiple streaming sites showing it.
It's safe to say Cascade is what caused Homestuck's boom in popularity. I started reading around that point as well.