Thanks! I just changed the style property "Message Text" of my site to set the font and it looks good but looking at the source code of your site I see this:
Unless the font is installed on a visitor's operating system it will not load that font. Open Sans isn't included in any OS by default as far as I know.
So to ensure that font is available to all users it can be served by Google Fonts. That's what that line does.
Thanks! I just changed the style property "Message Text" of my site to set the font and it looks good but looking at the source code of your site I see this:
As Chris said, it is to load the font so that the users can view it. There are also some resources in the RM for loading Google Fonts locally and not being dependent upon Google to serve them.