Comparing PublicIdentity.org with the white pages

In the days before the internet, we used phone books to find the phone number of someone we wanted to call.

Advantages

• The list included every phone number for the given area.
• Opt-out was monetized: you could pay for an unlisted number.
• There wasn’t any advertising, but you could pay to have your name in bold.

Disadvantages

• Each phone book only included numbers for a given area.
• Areas with a lot of people had huge phonebooks.
• Areas with a lot of people has a lot of duplicate names. They used address to help disambiguate, which is not currently desirable from a privacy standpoint.
• It was run by the phone company and only included people with phones.

Notes

This is directly comparable to what I want to build. I wouldn’t monetize opt-out, maybe I could charge for a bold listing.