If you have something valuable and valid whois, they will inundate you with unsolicited offers. I discovered my domains value by accident, with a unused whois only email I never checked for over a year or so. One day last year I checked it and the inbox was filled with what I thought was chinese spam, but in fact ton's of would be offerers. So I googled translated it and found out why. I found NamePros then too. So I put up a web page to translate a few things into chinese and a installed a contact form with "accepting offers". Then I waited for 9 months. Lots of 5-8k offers but knew it was worth more.
I discovered more about this market here on Namepros and
@Kassey Lee blog. Few if any real leads came from the website or from end users, mostly chinese brokers, I think I sent it to guta too, dont recall the offer or response. I put it on 4.cn, no real leads there either. Still incoming everyday from whois and not the website. I got over 300 of them, and not sure how many I deleted before starting to count them... there was so much interest. Finally I contacted another broker recommended by a well know domain blog and it was sold to a chinese investor.
I never published the name or price, but the investor was super happy to buy it that another competitor to the broker who sold it wrote on their well know chinese blog wrote a story on it.
The reason for all this info is I agree with the answers above. They WILL contact you, if there is interest. It might take a few months or a year.