I work in the online ad industry, and while you may hate even looking at the banner ads, I am often tasked with finding out who is running that banner ad. With aggregators, meta-aggregator, networks and exchanges, it is increasingly difficult to tell who is running on which site, and you need to check.
The good news is, this option is available on Safari too, although it is hidden. To enable it, fire up a terminal window and issue this command
defaults write com.apple.Safari WebKitDeveloperExtras -bool true
That's it. When you restart Safari next, you would see the Inspect Element option when your right click anywhere on page, and should you exercise that option, you would be greeted with a pane like the one below