As a blog advertising agency, brands pay our bloggers per post. PR agencies want 'real' conversations, how to pitch w/o eroding blogger's earnings?

I say to pitch the idea or 'outline' first. Have someone (on the payroll) responsible for sourcing opportunities, then ask your bloggers to pitch ideas. (For consistency's sake - consider bringing them together at a daily or weekly meeting?)

From there, pitch the ideas to the brands or agencies and paid the bloggers per post to flush out their ideas.

Pay-per-post is only successful / economical when the strategy is already developed.

You can't control whether someone else wants to have a conversation.

I've been blogging for almost 6 years, now with 40,000 RSS subscribers. I can tell you I have 0% ability to predict which post will be popular, causing lots of retweets and comments, and which are duds. Not time of year, not topic, not how excited I am with the piece, not length.

What that means, to me, is that you write a lot of good stuff and the conversations increase overall, but post-to-post it's necessarily unknowable.

That's OK, that's just the medium.

That's how I'd pitch it.

I've consulted with some of the largest blog advertising and online advertising companies in the world. Companies like IZEA (PayPerPost and others), MediaWhiz, etc. And I currently provide a robust Blogger Outreach service to many other large digital search agencies.

I'm not sure that I understand your question. But I think that you're asking how to get bloggers to talk about a client (or PR agency's client) without having it be a paid conversation?

This is tough if all of the bloggers in your network are used to getting paid. Chances are they really only run the blogs for the ad revenue, and not for an audience. That makes them a poor fit for PR agencies.

PR agencies contact writers and editors and pitch them ideas and story angles around interesting things their clients are doing. So you need to develop good creative ideas. One example is that at a previous agency I ran the CEO offered a gas subsidy program for employees who lived far away from the office and commuted every day when gas prices went really high at one point a while ago. So it was a BIG story in the news. Well we pitched our story to local media and within the week had them filming the story in our office!

If I did not answer correctly or if you would like more consulting I am open for appointments.

Behind every great brand story, you see in the media is a great PR strategy – and with the right strategy, you can turn your start-up into press-worthy news. If you have a deep understanding of the 3Ps, then you have undergone a critical phase in start-up development by articulating how your product or service aligns with the true and actual needs of your market. By mastering the 3Ps – developing a working product, knowing their customers’ pain points, and writing passionately for their audience – they were able to acquire thousands of customers while establishing themselves as an authority on all things social. Invest in relationships early on by giving something valuable before you ask for something in return. If you are wondering how to reach out to journalists and industry experts without it feeling forced or self-serving, look at natural opportunities to chat about topics that you both cares about, where you can add value. Instead, focus on providing industry expertise and knowledge.
You can read more here: https://neilpatel.com/blog/advanced-guide-to-startup-pr/
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath