Updn is effectively what valME.io [1] does (although valME has many more bells and whistles, doesn't require someone technical to install and run it, uses bitcoin and PayPal, etc.).
It is especially encouraging to see this open sourced. One of the goals of valME is to find ways where content consumers can bypass the behemoth publishing and media industries and financially support our favorite content providers directly. Could micropayments to bloggers, authors, writers, musicians, et al. not only add-up to an important stream of income but also provided significant competition to the publishing oligopolies?
I'd like to see the concept taken even further. For example, search engines: could upvotes/downvotes be used for search algorithm rankings, upending the SEO industry? How about books? What if authors published their books on open platforms where readers could upvote and/or tip the author as they read (e.g., "I really enjoyed that chapter, so I'm going to upvote it and give the author a few cents/bitcoins")? How about applied to the king of question/answer sites - StackOverflow? I know there are plenty of SO coders who deserve more than our non-tangible upvotes for the time and effort they saved us. Music? Upvote the song and give revenues directly to the band, bypassing the big media houses.
Advertising is currently the primary source of revenue for most websites and content providers. Micropayments based on voting and tipping could change this revenue model. What would happen if it did? Would content quality increase? Would it become easier for unknown content providers to gain visibility? Would search results become more useful? Would companies like Facebook and Google be forced to change their business models? Would copyright legislation become less relevant?
Technologies like Updn and valME are about upending the entire revenue model for news, social media, blogs, forums, and search engines - advertising. They could give unknown, quality content providers a real, viable alternative to working for the mainstream media or writing blog posts that aren't even getting a few pennies from Google AdSense. They could take power away from the entertainment lobbying companies. They could even help encourage teens to write and create outside of 140 characters, a snap of a camera, or a silly Facebook post.
But, philosophically, they can also help encourage a few thoughts that apply outside of what we do online. There is too often a belief that someone should get something for nothing; get something without effort; get something without paying for it; get something without trading for it. People forget that there is always a price for value. They forget that someone, eventually, has to pay. The Internet is a hotbed for reinforcing the idea of something for nothing.
We need to reduce the power of advertising dollars on the Web. We need to give content creators a different viable distribution channel to make money in order to reduce the power of copyright lobbying efforts. Directionally, Updn is a great way to do that and, as a competitor, I hope it is successful and we see more like it.
[1] valME.io - http://valme.io/c/gettingstarted/faq/kqqqs/how-valme-works/