Personalized Search

Recently, Yahoo! began to use their new ad system Panama and hopes to reduce the gap of money-making power between Google and Yahoo. From an article on December 26, 2006 of Business Week, I got to know that Tim Boyd, a financial analyst of Caris & Co. estimated that Google makes 20 cents per search while Yahoo! makes 10 cents per search. During a visit, I told this number to a friend. My friend said he got a different number and sometimes the number from a financial analyst should be double-checked. I agree with the viewpoint of my friend. Moreover, Jon Bentley also suggested that we should use “back-of-the-envelope” calculations, a standard fare in engineering schools. Here is my “back-of-the-envelope” calculation about the Google’s money-making power.

In Q3 2006, the total revenue of Google is $2.690 Billion according to Google income statement. According to Nielson//NetRating data, Google received 2.776 Billion queries (49% US search share) in July 2006, 3.003 Billion queries (50%) in August 2006, and 2.826 Billion queries (50%) in September 2006. Thus in Q3 2006, there are 8.605 Billion queries submitted to Google. If we assume that all revenue of Google comes from Ad (AdWord or AdSense), then on average Google makes $2.690Billion / 8.605Billion query = $0.31/query, i.e., 31 cents per query.

In Q4 2006, the total revenue of Google is 3.205 Billion. According to Nielson//NetRating data, Google received 3.022 Billion queries (50%) in October 2006, 3.098 Billion queries (50%) in November 2006, and 3.036 Billion queries (51%) queries in December 2006. Thus in Q4 2006, there are 9.156 Billion queries submitted to Google. On average Google makes $3.022 Billion / $9.156 Billion query = $0.33/query, i.e., 33 cents per query.

From the simple calculation of Q3 2006 and Q4 2006, we can see Google indeed makes around 30 cents per query on average. Since Yahoo! revenue comes from diverse sources, it is difficult to compute the Yahoo! number according to the number of Nielson/NetRating and Financial report.

Recently, Google pushes personalized search. They now have the personalized homepage, search history and personalized search results. I tried the personalized search and it seems that it is not clear whether they do personalized search or not for a specific query. I think it is one aspect that Google can improve, i.e., get each user informed when personalization happens and which results are personalized results. About this, Marissa Mayer said in an interview

One thing that we’ve struggled with is if we should actually mark the results are entering the page as a result of personalization but because team is currently and frequently doing experiments, we didn’t want to settle on a particular model or marker at this exact moment.

Marissa Mayer, VP of Google, said in the interview

The actual implementation of personalized search is that as many as two pages of content, that are personalized to you, could be lifted onto the first page and I believe they never displace the first result, because that’s a level of relevance that we feel comfortable with. So right now, at least eight of the results on your first page will be generic, vanilla Google results for that query and only up to two of them will be results from the personalized algorithm. I think the other thing to remember is, even when personalization happens and lifts those two results onto the page, for most users it happens one out of every five times.

I like the idea of combining personalized search results and generic search results together. In my thesis, I proposed progressive personalization. When the search engine is not confident about the user intention, it can present generic results to the user and at least must not annoy the user by pushing unrelated personalized results; when the search engine are confident about the user intention, it can push personalized results to the user.

In a summary, Google is pushing personalized search in a conservative way.

There are two talks related with search or search personalization.

One is a talk about search privacy, by Dr. Lorrie Faith Cranor, a professor at CMU.

The other is a talk about Secure Personalization: Towards Trustworthy Recommender Systems, by  Dr. Bamshad Mobasher, a professor at Depaul.

Today, I got to know that Findory, a personalized news website,  “rides into the sunset“.  It is a sad news. But I believe that personalization technology will succeed somewhere in the real-world applications.

I found that there is a talk by Dr. Alfred Kobsa, a professor at UCI. The title of the talk is Privacy-Enhanced Personalization. It should be very relevant to my thesis research on privacy-preserving personalized search.