Is it essential to use a developer key in Google Jsapi calls?

Question

I've been using Google Jsapi like so:

<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
    google.load("jquery", "1.3");
</script>

But the Google docs recommend doing this:

<script type="text/javascript" src="http://www.google.com/jsapi?key=YOUR_KEY_HERE"></script>
    <script type="text/javascript">
        google.load("jquery", "1.3");
    </script>

In my experience, it seems to work whether you include the key or not.

Will I encounter any problems if I don't use a key?

Answer 1

I don't think you need it for loading libraries such as jQuery, but the same loader is used for several other APIs such as Google Maps, which may require a valid API key.

Also, this is what Google has to say about using a key:

The API key costs nothing, and allows us to contact you directly if we detect an issue with your site.