Anytime you send an HTML message, AWeber tracks the number of times that message is opened by your subscribers.
You can view the opens for any of your broadcasts by visiting their "QuickStats" pages.
To find your "QuickStats" page you will first click "Broadcasts" under the "Messages" tab.
Here look for the heading "Sent", and just click on the subject line of the broadcast you want to see the "QuickStats" page for.
To see opens for all your messages at once, you can visit the reports page.
Go to your Reports page, under the "Reports" tab.
On the left side of the page you'll see a list of reports.
At the bottom of the page, choose "Follow Up Totals" or "Broadcast Totals" depending on which type of message you want to see stats for:
Your stats will display in a table and graph to the right.