How did Upwork Initially gain Traction

For those of you who used the sites early on, how did Upwork (or formerly Elance and ODesk) initially gain traction and users as they were starting up

It's always something that needs be created. I personally think that like every newb business, they started offering their own services as freelancers, then might invite their friends and started growing

I heard that at first they were an company that would find freelancers for other companies by since this took a lot of time and costed the companies a lot of money they just made it a marketplace like site so that companies/clients could choose freelancers for themselves.
How they grew the site after this transition I don't know?

Well Upwork is where it is because it combined the user base of Elance and oDesk.

Elance was actually created in 1999 but didn't hit it big for almost a decade.

Elance also spent a lot of early effort into creating software that seems to have done OK but was eventually dwarfed by their online platform. So if you take away anything from this it's that you need to find a need, success takes time, and sometimes you ultimately succeed when you veer from your original course.