Yeah, what I'm foreseeing is public and private links, tagging and the ability to search for links by page description, tags and user. The subscription fee would mainly be for hosting costs and an eventual commensurate salary. Even if the site were to gain traction I wouldn't be interested in selling ads based on user base size.

I'm willing to incur some hosting costs for a beta period but I won't fund the service for long without revenue if the hosting costs are prohibitive as I'm not really interested in selling it later for someone else to monetize with ads.