StumbleUpon has been a favorite of mine for some now. You've never heard of it? Well then, I'll explain. StumbleUpon allows users to "tag" websites. For example, if you are visiting this blog you might tag it "blog", "programming", "computers", "dave mackey" etc. In a sense tags are preferable to strict categories because one item can be in multiple categories. One is then able to define topics one is interested in (e.g. "computers", "search engines", "cars", "movies") and then "Stumble." When one stumbles a random website appears that has been tagged by others with your defined topics. You can give the site a thumbs up or a thumbs down and StumbleUpon will attempt to match your preferences with that of other users, over time refining which sites it displays to you. Its great fun - and a horrible time waster.
StumbleUpon's innovative usefulness has been evident by the massive amount of growth it has been experiencing. Recently this growth prompted an acquisition by eBay, the company best known as the way to buy or sell stuff on the web. eBay's portfolio also includes Skype, an extremely popular VoIP solution. With this acquisition it would seem that eBay is embarking itself for a bit of an arm's race with Amazon. Amazon is the other major retailer on the internet, but they have already embarked on a journey to make themselves about much more than products. Their product portfolio includes Alexa, a popular website ranking and search engine tool, as well as developer utilities such as S3, their distributed, remote storage solution.
In any case, this seems like a very wise move for eBay, but will it be good for consumers? I hope so. We will have to see how eBay plays their hand. From a financial perspective StumbleUpon is a gold mine. While they can continue to use advertising to support StumbleUpon they can also integrate eBay ads that reflect the tagged interests of the consumer into the stumbles - encouraging users to purchase eBay products through the auction and perhaps charging an additional fee for a "premium" spot in StumbleUpon results.
Consumers probably won't mind an occasional eBay auction appearing in the results if it is related to their topic - the key will be whether eBay can quickly determine the correct balance between their financial income and user's comfort. If they can't, then the acquisition by eBay could be a bad thing.
On the positive side for consumers however is a fresh infusion of capital into StumbleUpon and the public exposure that will come from being affiliated with eBay. eBay has a very large user base that it wants to have "stuck" to it, and using StumbleUpon and Skype as peripheral services is a great way to accomplish this. Furthermore, the financial resources of eBay are much deeper than StumbleUpon's and should allow for more rapid refinement in areas such as algorithms for ranking and anti-spam measures.