Let's say we take a look at the traffic details for www.canada.com - http://www.alexa.com/data/details/traffic_details/canada.com. Now, the graph size is 470?300.

Here's the how to hack the image: using Firefox, Click on the Rank tab, then right click on the image, and on View Image. This will display the image URL in your browser address bar. It may look like: http://widgets.alexa.com/traffic/graph/?r=6m&y=t&z=1&h=300&w=470&c=1&u%5B%5D= canada.com&x=2009-01-22T21%3A21%3A17.000Z&check= www.alexa.com&signature=CWfIVx%2Fb%2FBY2RiKpPxBPyMtNVzA%3D

Simply change the h=300&w=470 parameters to h=600&w=880 and there you are. An nice, bigger image.

Notice: all Alexa images have an expiry time, so if your image won't appear properly, you need to hit CTRL+F5 to refresh the page.

You can play with the other parameters to get control over the image:

r=7d/1m/3m/6m/max (translates into range equals 6 months)

y=r/t/p (graph type is Reach, Traffic or Page views)

z=0/1/2/3 (graph smoothness)

We've not been able to come with a trick to increase the time range (it used to be a max of 5 years ). If any of you know a way to hack that one (probably it will work with the Alexa API, not sure) let us know.