Why don't I see the text from Google's excerpt when I visit a site?

Question

Sometimes, after opening a Google search result, I discover that the text from the excerpt is nowhere to be found on that page.

Why does this happen?

Answer 1

It's not lying.

The content could be from a cached version of the page. However, in this case if you view the source for that page you find the following:

<div style="font-size:18px;font-weight:bold;padding:5px 10px;width:420px;
 border:1px solid #bcbcbc;background:#FFFFAF;"><a name="windowsffport">
 LastPass Portable for Firefox</a></div>

There are actually 27 instances of the word "Portable" on the page. It's just that the text isn't visible on the default "Recommended" tab of that page. If you click on the "Windows" tab that text becomes visible.

Answer 2

The description (which is sometimes out of date) is taken and stored in Google's cache and not directly from the site. The page can very well change from the time the page is cached. Also it's possible that the description is from a section of the page that is not visible (for example hidden div until some action is performed).

Why does Google display descriptions from cache instead of from the live site?

Imagine if every time someone searched, Google had to make a request to your page to get the actual live content. This would mean much more traffic and a lot slower results.