Twitter is the world's news paper now. I think, as world newspaper, it is worth it's value.
No matter what industry you are interested in, there are leaders worth following on Twitter.
One example for finance, Cliff Asness. He's a billionaire quant hedge fund guy, but he tweets every day.
There's a ton of investors, businesspeople, reporters, programmers, researchers, etc. that are very active on Twitter, not to mention the plethora of comedy accounts that I find hilarious.
One laaarge street corner.