Well, slideshare is 7 years old and is owned by LinkedIn, but I suspect that many of us here would consider it to be a startup.
20 50K salaries multiplied by 5 years is five million dollars in labor, never mind the overhead. If you've burned through that much cash and you're still in business after five years, congratulations. Unicorns aside, it doesn't matter if you're in the red or in the black. You are an established business, and not some fledgling twinkle in an investor's eyes.