But i'm not that kind of person
I wonder, when faced with it, who is? From around 2000 until around 2006 a lot of domainers were making a good living, and a few of them becoming wealthy, finding underutilized (premium) domains, emailing their out-of-the-domain-loop owners, offering usually $500 to $2k or so, and buying a super domain that was really worth five, six figures. They were doing this OFTEN.
Common strategy was to sit there, simply type in dictionary words or top phrases in dot.com, one after the other; if they stumbled across a website that looked underutilized, (as a fictional example) let's say they found Money dot com and the website was some cheap blog, not monetized, not much content; they'd email or phone the owner and offer a lowball amount (lowball relative to the actual value of the domain, but not lowball to the unsuspecting domain owner). Quite often you'd run across someone who had regged the domain for reg fee back in the '90's for personal interest, put a little content on the site, lost interest, didn't 'domain' so didn't realize there was any actual value to Money dot com as a domain name without the website, and would be pleased as punch to receive an offer to buy their Money dot com for a few thousand bucks.
Obviously that is not the story behind Money dot com, but it illustrates how the domainers worked. They'd simply run across underutilized domains (this was a skill, figuring out what kind of site looked 'underutilized' and like it was owned by a non-domainer and a person who wasn't really interested in the website any more), give them a phone call via their whois phone number, offer to do a deal, cash and fast via bank wire. The unsuspecting seller would be thrilled to receive a nice big chunk of instant money for a domain he's no longer even interested in... finding out a month or years later that he'd sold an $xxx,xxx domain for low $xxxx.
The domainer's trick was to offer just enough money so the domain owner would think it was a good chunk of money and not a rip-off. If they were excited about the offer amount, they'd be less likely to 'start looking into things and asking questions'. "Three grand!?? For just my domain, not the website??!! Hell it only cost me reg fee for 10 years, SURE I'll take three grand for it!!" Then you've bought, like, airplanes dot com for three grand, and the retired old pilot who thought it was worthless is thrilled. With luck he dies before learning you sold it a month later for $2mill.
Another method was via obsolete email addresses. Some domainers used services or scripts to send blank or almost blank 'exploratory' emails to addresses mined from thousands of websites thru search engines. If any emails bounced back as undeliverable, the domainer would check that website's domain and if it was high quality, would use other methods to try find the contact info of the owner. That whois email addy might be defunct but the owner's phone and land mail addy might still be correct. The thinking was that if that website owner's email was defunct, they probably don't pay much attention to their website and online properties and might not know the value of that domain they own.
There were other tactics, but these two were the most common in this strategy of 'bilking unsuspecting owners out of their valuable properties'. We all try to buy low and sell high, that's the name of the domain trade game. I guess each person has to define for themselves what's fair and what's bilking. I still try to buy things at reseller prices, pay a few hundred for a domain I think I can sell for a few thousand. I think that's fair and honest.
So, back to your statement 'I'm not that kind of person'. I myself probably was... if I'd run across a domain 10 years ago, that some unsuspecting owner was happy to receive $2k for, and let's say it was a high quality premium I knew was worth $500k... would I have just told him? Or would I have told him and offered to help with the sale as a broker? Or would I not have told him, paid the 2k, and sent him a Big Mac hamburger later as thanks (I could order it via phone from my new airplane) once I sold the name for a stinky big profit?
I don't know about back then. I think I'd have done it. Nowadays, I am positive I would just tell them. For the karma, it's who I am. A karma-sucker, I guess. Karma-fool.
At any rate, roundabout 2006 - 2007 so many domainers had scooped up those underutilized valuable domains for dirt cheap that you just couldn't find them any more. Domainers who were previously scooping a few of those each month, by 2006 were lucky to scoop one a year, if any at all.
There are still owners out there who unknowingly have premium domains, but the ratio is so low now that finding one is akin to winning a lottery. Extremely rare, for the super premium domains in the 5 or 6 figure range. But there are still quite a few unsuspecting owners of lesser domains, say valued at 4 or low 5 figs. Those owners are a little easier to find... but nowadays so many people are tied into their online projects that even if they don't realize their domain is valuable, they still want to keep it and they turn down lowball offers. And even if they don't know about 'domaining', people are so much more quick to check things out now than they were 12 years ago, they'd probably spend a few minutes looking into domain forums before accepting an offer... and then they'd find out that maybe their domain actually does have substantial value.
Hey, who did all this writing? Must be a lazy day.