There are a dozen bookmarking services out there, many of them quite well done. However, most services are focused on the idea that bookmarking is a lone-person habit, which someone does in isolation.

I've often described the idea as "dropbox for bookmarks". The core concept is to allow a bookmarking "tag/folder" to be shared with another user, two-way. This means any of the shared members can add/remove bookmarks from that folder. All updates (addition/deletion/edits) are notified to every member in the group.

Bookmarking for Teams, in essence. Some good alternatives are https://www.quora.com/Hello-What-are-the-best-web-apps-for-sharing-bookmarks-across-a-team which you should read and follow if you're interested in this.

Stacks is more than just a bookmark manager. It’s your team's second-brain that helps them remember everything they find important online.

It provides:

• save and share bookmarks with one click - Chrome
• see it in recommendations while searching in Google
• Easily search for the saved bookmarks
• See what other team members in the company has saved so the duplication of search doesn't happen.
• create a personal and shared repository of knowledge
• you can have a shared space with your partner/spouse to share everything you like - instagram videos to places to visit without creating hundreds of message notifications. Android

They will find information from shared repository when they want to, not when you want to share.