FYI, our TOS doesn't allow members to suggest/recommend specific website. We also avoid suggesting specific search queries as they can/tend to serve as "easy cover" for some people to promote their website. Fortunately, finding a place to list a business for sale is as easy as performing simple, very general queries relating to listing a business for sale, businesses for sale, sell a business, businesses for sale, etc. It's pretty much a no-brainer to identify potential sites.
Study the sites. See the quality of the listings. There is SO much junk for sale. It's hard to rise about the noise.
Sites that eventually sell, sell because of the quality of the website, its ranking, the quality of the inbound links, the age of the site, the quality of the domain and the sites lack of concerted optimization effort, etc.
One of the perils of listing a marginally successful e-business for sale is that . . well . . it's the WWW. IF you tout your site's success that can inspire some to seek to enter the market and compete. Others may use the public info to suggest your business is unsound. (What happens if a query for your website brings up your listing info?)
Desirable websites, just like desirable domains, tend to attract purchase inquiries without any marketing or selling effort.