Del.icio.us Founder

Josh Schachler, founder of del.icio.us, visited my E-Business and Data Mining class this week. He discussed the evolution of his company, how he decided to develop certain features versus others, and how del.icio.us has grown and why he believes it will continue to grow.

A couple factoids that he shared with the class:

• 2 million users as of February 2007
• The median user creates 30-40 bookmarks/week (with 2 tags/bookmark)
• 90% of bookmarks are unique, with 1/2 million URLs added per day (compared to a couple thousand for Digg)
• The most popular sites are google, slashdot, yahoo! and amazon

We also discussed the site's dynamic behavior over time. Andreas mentioned that in e-commerce, the second purchase is extremely important as it sets a pattern--this is clearly true in del.icio.us as well. In the beginning, Josh said that 1/3 of users who signed up bookmarked one URL, and of those, 1/3 used it again a week later. However, after 2 weeks there was little drop off.

The intended users of del.icio.us are definitely people who swim in lots of information; they are unable to keep track of URLs strictly through their homepage and bookmarks on their web browser. The site works so well because the cost of saving items is very low (this helps grow the network effect). Del.icio.us eventually has developed into a very light weight blog in this sense.

Josh has definitely made strategic changes to curb the social networking portion of the site. For example, there currently is no mechanism for messaging between users; his reasoning for this is to avoid negative interactions such as edit wars at wikipedia. He also was against the "hotlist" and other types of high score lists as they encourage strong negative second order effects on the system (ie. gaming).

We also discussed how similar del.icio.us is to other bookmarking sites like digg. Those sites tend to be more discovery oriented, whereas del.icio.us is intended to be more of a human-driven search engine. One statistic that demonstrates this type of usage is that only 8-10% of tags are on the most popular URLs; the tail of this distribution is very, very long. Josh also mentioned that Kevin Rose, the founder of digg, also uses del.icio.us.

In addition, Josh mentioned how he grew del.icio.us, and his reasoning for the Yahoo! acquisition. He said that they placed RSS on every page, created an application that easily migrated the bookmark of the day to a user's blog, and offered API for individuals to build functionality on top of the system. Del.icio.us can also import and export bookmarks very easily. Yahoo! provided the scaling technology that has allowed del.icio.us to grow at such a tremendous pace (from 300 thousand users in December of '05 to 1 million users in September of '06, and another 1 million users in the past 5 months).

One interesting aside is how Josh got the idea to create a bookmarking site. He was a trader for Morgan Stanley before starting del.icio.us, and built the site to create an interesting dataset to analyze. His says that his first focus was on the individual user, and the social aspect of the site was only a secondary concern. Del.icio.us itself is one of many sites that Josh purchased when the .us domain became avaiable in 2001. He wrote a program to determine what are the most common suffixes that end in 'us', and 'icious' was the winner.

E-Business and Data Mining Class

I am currently taking a class on E-Business and Data Mining from the former Chief Technologist at Amazon (Andreas Weigend). The class has been extremely interesting--so far we have analyzed search, including web crawlers, PageRank, and the economics behind Adwords. For my homework assignment, I am keeping track of how many people click on the following link using Google Analytics:

http://www.weigend.com/Teaching/Stanford/