Google: Introducing the +1 Button

We all know what it’s like to get a bit of help when you’re looking for it. Online, that advice can come from a number of places: a tweet, a shared video, or a blog post, to name a few. With Google Social Search we’ve been working to show that content when it’s useful, making search more personally relevant.

We think sharing on the web can be even better–that people might share more recommendations, more often, if they knew their advice would be used to help their friends and contacts right when they’re searching for relevant topics on Google. That’s why we’re introducing the +1 button, an easy way for Google users to recommend your content right from the search results pages (and, soon, from your site).

+1 is a simple idea. Let’s use Brian as an example. When Brian signs in to his Google Account and sees one of your pages in the organic search results on Google (or your search ads if you’re using AdWords), he can +1 it and recommend your page to the world.

The next time Brian’s friend Mary is signed in and searching on Google and your page appears, she might see a personalized annotation letting her know that Brian +1’d it. So Brian’s +1 helps Mary decide that your site is worth checking out.

We expect that these personalized annotations will help sites stand out by showing users which search results are personally relevant to them. As a result, +1’s could increase both the quality and quantity of traffic to the sites people care about.

But the +1 button isn’t just for search results. We’re working on a +1 button that you can put on your pages too, making it easy for people to recommend your content on Google search without leaving your site. If you want to be notified when the +1 button is available for your website, you can sign up for email updates at our +1 webmaster site.

Over the coming weeks, we’ll add +1 buttons to search results and ads on Google.com. We’ll also start to look at +1’s as one of the many signals we use to determine a page’s relevance and ranking, including social signals from other services. For +1’s, as with any new ranking signal, we’ll be starting carefully and learning how those signals affect search quality over time. At first the +1 button will appear for English searches only on Google.com, but we’re working to add more languages in the future.

We’re excited about using +1’s to make search more personal, relevant and compelling. We hope you’re excited too! If you have questions about the +1 button and how it affects search on Google.com, you can check the Google Webmaster Central Help Center.

How Google Earth displays dates on their imagery

As you probably know, when you’re looking at an area on Google Earth, the date the imagery was captured appears in the lower-left corner, as shown here:

imagery-date.jpg

However, what does that date actually mean? As some of you have pointed out, the date doesn’t always correspond with the imagery (snow on the ground in July, etc).

For standard satellite images, it’s simply the date the imagery was taken, which makes sense. Easy enough. The discrepancies arise when Google loads imagery for a large area from a commercial aerial provider. In those cases, they’re given a range of dates for the imagery. The date you see on the screen is the “oldest known date” for that imagery, while the tic mark in the Historical Imagery sliders is the “newest known date”. In many cases, those date ranges can be up to a few months apart.

To confuse it further, some providers don’t even have exact dates for a batch of imagery; they might simply say “April-June, 2010”. In those cases, Google considers that to be “April 1 – June 30, 2010”, and then displays the date as explained in the previous paragraph.

While the system obviously isn’t perfect, it’s certainly improving. Google Earth didn’t start showing the date in the corner until version 5 came out (so you had less of an idea of when the imagery was captured), and the Historical Imagery tool was certainly a great addition to Google Earth.

As the pace and quantity of imagery updates continue to increase, I expect we’ll see some refinements to this system over the coming years to help it become even more accurate and useful.