The Social Bookmarking Faceoff

The Social Bookmarking Faceoff
Written byAlex Iskold and edited by Richard MacManus.
The social bookmarking market is in a steady state with two dominant players -del.icio.us andStumbleUpon. The rest of the pack, including Yahoo MyWeb, appears to be substantially behind. Will they catch up? In this post we attempt to answer that question.
We also take a look at how social bookmarking has evolved since del.icio.us. (even del.icio.us itself has evolved a lot!). We compare the features and approaches of the different companies, to see which has gained popularity and what has become the norm in this space.
A short history of social bookmarking
The current social web era started withdel.icio.us and the advent of social bookmarking. The simple concept of a tag has turned our interactions with the web upside down. The idea of being able to store your bookmarks online, share them with everyone and see what others have bookmarked - triggered the sequence of events that resulted in today‘s rich and social web ecosystem.
We used thee-consultant andgo2web20 lists of social bookmarking services to select the companies. Note that we did not include any company with an Alexa rank of less than 100,000. We also did not profile social news sites (like digg) or social shopping sites (like Kaboodle), as they will be profiled in separate R/WW posts.
Feature comparison
Note: Mouse over the column headings to see full text
Site Imp Pop
Rec Rel
Dir Frd Rat Pri Tag
sug RSS Wid Brw API Pros Cons

BlinkList
Alexa: 3,600
Technorati: 63,794 x x x x x x x x x x   BlinkSpaces - create a community out of your links, nice browser toolbar, all and all really nice. A few broken links in places, a bit underdesigned for my taste.
Blogmarks
Alexa: 9,000
Technorati: 48,331 x x   x   x           Nicely designed, generate a post of your bookmarks for your blog Seems incomplete compare to other sites. Injects ads. Crashed several times during my tests.

del.icio.us
Alexa: 155
Technorati: 1,597,818 x x x x   x x x x x x Easy to use, intelligent, tons of useful features, not in your face Not fancy, might not appeal to the main stream.
Site Imp Pop
Rec Rel
Dir Frd Rat Pri Tag
sug RSS Wid Brw API Pros Cons

diigo
Alexa: 13,750
Technorati: 2,262 x x x     x x x x x   Post to other bookmarking services, supports annotations with sticky notes, flexible blog integration. A lot of options, might not be easy to learn for everyone, mixes a lot of things together.

Furl
Alexa: 2,400
Technorati: 126,000 x x x x x x   x x x Has archiving, simple browser add-on, has some additional options associated with the post. Lacks related items, could use a re-design.

Ma.gnolia
Alexa: 9.400
Technorati: 82,800 x x   x x x x x x   x Beautiful design, nice implementation of groups, well thought through Does not look very active, lack of browser add-ons and imports, lacks unique features.

MyWeb
Alexa: 1(for Yahoo!)
Technorati: 76,000 x x   x   x x x x x x Nice look and feel, could work for main stream. Too many things in the toolbar, falls short of del.icio.us on many features.
Site Imp Pop
Rec Rel
Dir Frd Rat Pri Tag
sug RSS Wid Brw API Pros Cons

Shadows
Alexa: 13,000
Technorati: 11,140 x x   x x x   x x x x Fairly comprehensive set of features, clean design Popular is done by tags instead of by links, site is somewhat slow, does not feel as connected as del.icio.us

Simpy
Alexa: 14,600
Technorati: 35,000 x x x x   x x   x x x Instantly view current page history, browser export Could use UI improvements, no popular links, similar links are not cross users, too many first level menues in Firefox extension

StumbleUpon
Alexa: 617
Technorati: 33,500   x   x x       x x   A different approach, that seems to be successful, given the number of users. Nice browser toolbar. Would be great to have directory and browse related.
Estimating the number of users
Companies typically do not reveal the number of users and activity, but we can do educated estimates. In a recentpost on TechCrunch, Michael Arrington stated that there are about 53 million posts on del.icio.us. Based on the statistics mentioned at the time of the del.icio.us acquisition (by Yahoo) in December 2005, and the growth since then, we estimate the current number of people using del.icio.us at 500,000 [UPDATE since this post was first published,del.icio.us announced they have 1,000,000 users]. From this we conclude that the average user on del.icio.us did a little over 100 posts. This is a pretty impressive number, although it might be the case that there is a fat tail and a handful of users with a huge number of posts.
If we use 100 posts per user as a guide then, we can do similar estimates for other social bookmarking companies. For example, since Blogmarks has a total of 514,205 posts, we estimate that they have roughly 5,000 users.
Here is another interesting angle... a search on Yahoo MyWeb for items tagged "food" results in 7,200 bookmarks. A similar search on BlinkList brings up 120 pages with 20 items per page - or 2.400 bookmarks. In other words, the number of posts tagged with a particular word or term can be used as another relative measure of the number of users.
Finally, here is another method for estimating the number of users. We took a recently popular web2.0 list url: go2web20.net, as well as all time favorite CNN.com, and looked at how many people have bookmarked these on various services. If we do this for a hundred or so randomly choosen URLs, we would get more precise estimates - but this is just to give us an approximation of the number of users. Here is a table showing our results:
Site Links to go2web20.net Estimated users based on go2web20.net Links to cnn.com Estimated users based on cnn.com
BlinkList 40 14,800 568 38,200
Blogmarks 5 1,800 56 3,700
del.icio.us 1,354 500,000 (baseline) 7,429 500,000 (baseline)
Diigo 21 7,750 32 2,150
Furl 53 19,600 200 13,500
Ma.gnolia 9 3,300 51 3,400
Shadows 1 370 21 1,400
Simpy 9 3,300 312 21,000
Stumble Upon   1,271,345 (public)   1,271,345 (public)
NB: With MyWeb, the estimated users is 114,600. As it turns out we can‘t compute it with the same method, because information is not quite there. Instead, we used the Tag Comparison method and compared it with BlinkList.
Conclusion
The social bookmarking market is dominated by del.icio.us and StumbleUpon. These leaders split the market, as they bring orthogonal approaches to bookmarking - del.icio.us builds a hierarchy for people to browse (it does related relationships, etc.), while StumbleUpon is more of a random discovery system.
Meanwhile the other players in this market have a lot of ground to make up on the two leaders, based on our analysis in this post.