Infographic from 2010: http://techcrunch.com/2010/07/27/digg-reddit-infographic/
Reddit has registered users submit links or a text post, then other users can vote it up or vote it down, which is the ranking system for the post. This rank will determine the position of the post on the page. Registered users can customize what is on their personal front page by subscribing to individual reddits through a page that shows all reddits available. The look is relatively simple, with a tiny thumbnail at most for images. There are also "promoted" posts which are sponsored by companies that show up on top. Based on the infographic, their main type of postings are images, and then reposts from Reddit.
Pros:
- Simple site layout
- Sponsored link easily noticeable and always on top of page
- Maybe looks too simple
- Too many subtopics on the top of page that new users may not know what the term is
- Hot pages show up first, not most recent
- Controversial tab is a hit or miss
Digg also has registered users submit links/text posts, and other users can vote up or vote down. Digg shows the most recent post first, but only after it hits a certain number of up votes (to weed out the spam posts). This doesn't determine the position on the page, but if a story has enough up votes, it can be moved to the "Hot Stories" (which only lists 5 on the front page) or "Top News" (which lists 10) section on the page. The look is more sophisticated than Reddit, and most of the posts include a thumbnail image as well. There are also promoted posts, however it is sorted within the recent news, but it is noticeable with a yellow bar showing "Sponsored by ___."
Pros:
- Sophisticated site layout
- Sponsored link easily noticeable
- Shows most recent posts with enough up votes first
- Shows hot stories and top news stories on the front page as well as recent.
- Sponsored link is sorted within the links, so it is less noticeable than Reddit's sponsored link.
- When clicking on a story, it goes to the site with Digg's toolbar up top, no option to automatically skip it.
- Much more new front link pages compared to Reddit.