I had a good idea (IMO) for creating a possible authority site today (inspired by looking at the top lists on Alexa.com). Without giving away the idea, the aspects of it are:
* It must have a social aspect (members, comments, votes, sharing)
* Should feature videos
* Encourage user-contributed content
* Be brandable - most traffic will come from social networking
* Data-mine content from sites in the niche (such as the feed) to feature in listings (run software to update the site content)
* Link back to the featured sites to send them traffic - get the webmasters on board (make them VIP members)
* Special sauce - this is the bit that adds value to the above :)
So the idea is to have features that are common in the top sites, but also add something new to make the site interesting to visitors. And a key factor is to not have to write tons of content your self. We want to have 1000's of pages of unique content.
But, it will have to be custom coded. There will be a template, engine, and data-mining software involved.
If the site takes off, there should be lots of monetizable traffic. If not, then try another niche with the code already developed.
p.s. I just registered a suitable domain name.
On the design side - it should have a modern feel, and adopt elements of the top sites.
Instead of a subscribe form, I am thinking of a left-side profile panel (but need to avoid link-building spam) that is like a blank template waiting for the visitor to fill in to become part of the community. So the profile is like in FaceBook.
The main content will be featuring the buzzing community content that the visitor will feel compelled to join.
And for mobile device optimization, I am thinking about floating the content blocks so they flow into the visible browser window. Maybe like pinterest? Have to study how they do it. None of the dated, centered column website design.
And again from FaceBook, have a chat column with alerts of friend activity. Friends will hook users into staying with the site.
Also, to get a great user experience: I am thinking to use Ajax, and cookies to have the user input go live immediately as far as they can tell, but it will still be subject to moderation before it goes live to the world.
So: low barriers for entry of new users, compel people to join, make it fun, make it work well on computers and mobile devices, don't make people wait to be approved, inter-twine the members socially so they become friends and don't want to leave the community, make it look and feel like a web 2.0 site.