Google shareholders who have a few extra thank you notes sitting around might consider sending them to AT&T, the Apollo Group, and Expedia, along with a handful of other companies.  New data identifies these organizations as the biggest AdWords spenders in June (and pins down the dollar amounts involved).

Michael Learmonth apparently obtained "an internal Google document," and it showed that AT&T spent a whopping $8.08 million with Google in June alone.  The Apollo Group, which owns Phoenix University and several other institutions, spent the next largest sum: $6.67 million.

Then, thanks to the graph Learmonth created, you can pretty well see how the rest of the lineup worked out.

One atypical thing worth noting is that BP doesn’t usually rank so high; its spending was mostly an attempt at damage control following the Gulf oil spill.

Otherwise, Learmonth noted, "The document shows 47 advertisers that spent more than $1 million in June; 71 that spent between $500,000 and $1 million, and 357 that spent between $100,000 and $500,000.  These are direct-billed customers only, not the many thousands of small self-serve advertisers that make up Google’s long tail, a key component in its $23 billion global annual revenue."

Maybe scratch the thank you note idea, then, since stamp costs could become quite high.