Ask HN: How run a successful digital marketing campaign, on a shoestring budget.

I recently read about orabrush story, on how they used youtube as a medium to spread awareness about their product. I would like to know more of these types of successful and creative marketing campaigns that actually worked for digital products or atom products.

Also, I would love to hear tips and tricks for a successful marketing campaign, with very limited budget.

If you have links to some precious resources or books to read, please mention it.

Thanks.