This is the sometimes shocking truth that most people ignore when they use free web products without wondering why and how those companies provide them for free.

Afterall, if you think of it, to install that wireless connection in your home you pay the cable company, the cost of the router and the electricity to make it work 24/7. And this is just enough for one family and within 20 feet of radius. An airport definitively needs more, so why Google is so happy to offer you that for free?

And what about GMail? It is a wonderful free product and you have 8Gb of space for your emails. On the other hand, buying 8Gb of memory card for your camera arts you back of $20.

Google Chrome is a great browser but why would Google invest the salary of 50 of its own engineers to develop a free browser while there are already plenty of alternatives out there? Why Yahoo would develop a special toolbar to put in your browser while there is already a search box on the top right corner of it?

There are lots of other examples like those on the web. Almost all free software (e.g., if you installed uTorrent it came with Ask.com toolbar) on the Internet comes with a toolbar nowadays.

The answer is simple: they want your data.

Those companies are not looking for your address or SSN. They are interested in your hobbies, the news you like, which pages you visit, and what you buy. They are trying to create a profile of you and then use it to provide better targeted ADs, increasing the likely-hood that you will click on them and therefor make them money.

Clicks and time spent on each page can also help web search engines to improve and train their ranking algorithms. If everybody stop a 5-minute YouTube video after a couple of minutes, it is probably not that great. The same goes for a page full of text abandoned after a few seconds. On the other hand, if the average time spent on a page is 3 minutes, and you spend there only one, it is probably just not that relevant to you.

GMail is a great example of this technology. While you read your email, perhaps discussing the recent vacation of your pal in Hawaii, the servers of Google are busy at work extracting the important keywords from those messages and providing you flight and vacations offer on the right side of the screen.

The free WiFi that Google offered around the Christmas holidays allowed them to gather plenty of data on what people were buying this season, information that could then be used to improve Google Checkout. At the same time, they could monitor in real-time which news people were looking at, which definitively helped improve Google News.

Should you stop using all those products? You cannot, we both know it. However, you can take steps to reduce your exposure: delete all the browser toolbars (what do you use them for, anyway?), start using a free browser like Firefox, and install extensions like CookieSafe and Adblock Plus.

Here is the percentage of time spent reading the snippets compared to the percentage of clicks done on the results.

         eye     clicks
   1    28.43%   56.36%
   2    25.08%   13.45%
   3    14.72%    9.82%
   4     8.70%    4.00%
   5     6.02%    4.73%
   6     4.01%    3.27%
   7     3.01%    0.36%
   8     3.68%    2.91%
   9     3.01%    1.45%
  10     2.34%    2.55%

The eye-tracking data can be especially useful for who is trying to train a relevance/ranking system and uses Discounted Cumulative Gain as metric.

Below you will find some of the pictures I liked the most. What do you think? Pretty impressive, uh?

Due to my researches at the University of Iowa, I look at the Twitter stream at least twice a day. After reading the Mashable article in which they claimed that looking at Compete’s numbers Twitter growth flatlined, I decided to take a look by myself.

According to my most recent studies Twitter currently receives about 26 Million tweets per day. It is impressive, especially if you consider that in January 2009 they were hovering around “only” 2.4 Million daily tweets!

As you can see from the graph attached to this post, the number of tweets started growing exponentially at the end of last year (2008), but decreased this month, going from an average of 27.8 Million tweets/day in September 2009 to “only” 25.9 Million in October 2009.

Twitter usage patterns changed drastically since they started. Long gone are the days in which it was used to keep in touch with friends and family, nowadays a growing number of people use this service as an RSS feed reader or to share pictures, videos or links that they like.

My latest analysis of the stream say that in October 2009 about 22.3% of all the tweets contain a link. We are talking about almost 5.8 Million of URLs exchanged every day! Of those, 6.2% are pictures and almost 0.1% are videos.

No wonder many companies (e.g., OneRiot, Collecta, Tweetmeme) started fetching and indexing those links to create human-powered realtime search engines. And now, Bing and Google are in that game too.