It seems like the question is talking about large, zero-revenue startups. Ecomom definitely doesn't fit here, since they were collecting over $1M/month in gross

It seems like the question is talking about large, zero-revenue startups. Ecomom definitely doesn't fit here, since they were collecting over $1M/month in gross revenues. Of course, they were discounting so much that each order had a negative margin, but that is a different story. I think the most dramatic example of this (other than WhatsApp) is Snapchat.