At one time, CEO Eric Schmidt blamed rising headcount for having an impact on Google’s numbers and claimed Google would get that under control.

That worked as well as turning a new Googler in the direction of the free cafeterias and snack bin, and saying try not to eat too much. Consumption aplenty happens, with the expanding bottom line as a result.

In July 2007, Google reported operating expenses of 31 percent of revenue. Schmidt said they overhired during that quarter, and promised to keep an eye on headcount.

Judging by what Paid Content found in the grease trap of the customary annual 10-K filing, Schmidt may be a little nearsighted about what the recruiters are doing under his watch:

Our full-time employee headcount has significantly increased over the last 12 months, growing from 10,674 at December 31, 2006 to 16,805 at December 31, 2007…consisting of 5,788 in research and development, 6,647 in sales and marketing, 2,844 in general and administrative and 1,526 in operations.

Six thousand people don’t just slip in the backdoor and start pounding out code. Google expanded to other locations domestically and abroad during the year. Expansions need to be staffed, and given access to M&M’s.

The biggest figure on Google’s annual report remains its revenue stream. 99 percent comes from online advertising, with 48 percent of total revenue coming from international sources in 2007. The company also noted how its fortunes follow the typical pattern seen in retail:

Both seasonal fluctuations in internet usage and traditional retail seasonality have affected, and are likely to continue to affect, our business. Internet usage generally slows during the summer months, and commercial queries typically increase significantly in the fourth quarter of each year. These seasonal trends have caused and will likely continue to cause, fluctuations in our quarterly results, including fluctuations in sequential revenue growth rates.

One other headcount note: despite announcing a forthcoming retirement, CFO George Reyes has not set an effective date for that departure. He first said in August 2007 he planned to retire from the company.