Ask HN: Are there examples of web/digital agencies going IPO?

I want to know if there are some digital agencies that are "true startup", that is, they have the intention to expand business to go IPO sometime in the future, or at least become acquired by a larger company.

All the digital agencies I'm familiar with are small-ish, and many have a "startup vibe" with the work culture. But I won't consider them startups since they don't have an intention to IPO. But is it possible to take such an agency to IPO? Or is there something inherent in the nature of digital agencies that will make them difficult or impossible to scale to that point?