He didn't explicitly state that it was his best month by total revenue received. It read more to me like 5 x 5 figures sales was a first, led him to declare it to be his best month ever. He doesn't implicitly state anything like "$300k is the most I've ever made in a month".
But lets assume that you are correct, and that for 10 years he has been spending $2.5m a year maintaining a portfolio which generates a loss of about $1m a year.... (I doubt it, but lets do it that way for arguments sake)....
... why does it matter to you? Its his money isn't it? And perhaps you have a poor understanding of business in general. A business can generate a loss on the balance sheet whilst being worth a lot of money on paper. What if Mike Mann ran his domain portfolio at a $1m per year loss, for 15 years, but then sold all domain assets for $50m? He'd be making a $35m profit then wouldn't he?
Twitter has never made a profit. That doesn't mean that twitter is worth $0, it has a market cap of $18bn.
Domains are an asset class. So perhaps Mike Mann could generate a greater profit if he priced his domains more reasonably and generated cash flow, but then he'd be losing assets (domains). It actually makes more sense for somebody who is cash rich and doesn't need to draw on the business to concentrate on book value / asset value, especially if he wants to 'exit' again.
He could 'turn on' the sales by pricing competitively to generate a black line at the bottom of his P&L, and sell a year later. He doesn't have shareholders who expect dividends each year, and he doesn't need the salary, so this is why I question whether you understand business. You seem to think he should be liquidating assets faster and drawing profit out of the business annually, but he has already demonstrated once to the world that the money is to be made in selling the assets in one go.
Perhaps he is doing exactly what he did last time, and that worked out pretty well for him. You have your way of doing things, but you haven't sold a domain portfolio for $80m have you... when BuyDomains was sold, they weren't purchasing based on 10 years of P&L, they were purchasing on what they thought the value of its assets were.
There is a 2012 article on thedomains.com which reported a YTD revenue of $526k (for first two months) from 659 domain sales in two months. So $526k x 6 = $3.156m.
He had around 300k domains at the time, for renewal fees of around $2.5m. So that would be a slim profit based on those types of numbers. If you can call circa-$600k 'slim'.
https://www.thedomains.com/2012/03/...ls-almost-300000-in-domain-names-in-february/
What you are also not considering in this equation is that footer links on his website pages which lead to SEO.com and Phone.com..... how much do you think two banner ads at the bottom of 300,000 different domains is worth? Probably easily enough to justify the type of losses you are talking about.... I wonder how much business that generates for those two other businesses of his?
Perhaps you are missing the picture there. What if his domain portfolio costs him $1m a year, but drives $10m worth of business to phone.com?
Nothing is ever black and white, but I think we can all be pretty certain that Mike Mann is too shrewd to have spent 10 years setting fire to his money, you aren't thinking outside of the box enough. He's probably a genius....
..... may lose $1m a year on his domain portfolio (may), but it could be the cheapest form of advertising he could find for the SEO and Phone niche (go and look at the cost of acquisition via adwords for those niches!).
If a domain costs $9 to renew, but each drives an average of 3 clicks to seo.com or phone.com.... it has paid for itself in customer acquisition value alone compared with cost of acquiring that same customer from adsense or linkedin.
