Re: What's their Angle?
>> Yeah, but what's in it for them?
Ad impressions. There are three things to consider: First, that displaying ever-changing results as you type equates to the user searching multiple times in a row. This exposes him to more ads (each search result is presumably for different search criteria) in a short time.
Second, that the distraction may lead to users not finding what they are looking for--that is, unless Google Instant is really *that* good and actually guesses what it is the user is searching for.
Then third is the placement of the ads themselves. "Sponsored Links" occur at the top of the page, right below the search box. So, while users are typing in their criteria, they are exposed to more advertisements in a prime location.
Now, Google claim that they only charge for a click-through, not ad impressions; but as the article suggests, ad impressions influence the click-through rate and the overall weight of advertisements themselves. This means that, with more impressions, the click-through rate may be higher, therefore earning them more money.
Another possibility not even considered by the article is that Google can eventually change their model to an impression-based on. They could be doing this right now, negotiating with their partners regarding how to best exploit the additional impressions they will surely get.
In short, what's in it for them? More money, of course.