Ask HN: How did you solve the chicken or the egg of advertising?

Being new to the advertising industry, the biggest issue we have faced as a company has been that advertisers like our product, but need to see a certain scale before they will play with us.

Hoping to hear from anyone who got ad revenue early on and grew with their advertisers, versus the more traditional route of raising money by showing user traction and worrying about advertising revenue later.

What creative ways did you get big brands (or not so big brands) on board before your product was sizable enough to matter to them?