I just read a nicely put together story about WooCommerce over on the CodeinWP blog. WooCommerce started life as WooThemes, sort of a "premium themes" business started by just a couple of fellas who had never even met in person. Two years and a few employees later they launch WooCommerce, and 2 years after that it hits a million downloads. A major success story, to be sure, but a collaborative and remote-work based one that wasn't exactly overnight. Another 2 years and Automattic picks them up and the WooThemes part is spun down.
Now we're 3-4 years into WooCommerce being an Automattic project and it's looking at nearly 60 million downloads, 4 million of which are active. A number they are saying is about 30% of all eCommerce on the web. Daaaaang. I've used WooCommerce a number of times and it always does a great job for me.