If you read through the press release and supplementary information for ExxonMobil's (NYSE:XOM) latest earnings report, you will be inundated with numbers -- how much it cost to do this, how much it could get for selling that. Earnings cover nearly every geographic location and business segment, and a whole bunch of other things that might make the energy giant's overall earnings picture look a little hazy. But of all these numbers, one matters more than the rest: $2.6 billion.

This is how much cash the company generated from its entire business after you subtract capital expenditures for the quarter. Let's look at why this number is so important to the company, and what investors should take away from this. 

Come for the oil, stay for the cash
If you are looking to invest in ExxonMobil -- or any other integrated oil and gas company, for that matter -- then chances are you aren't looking at this company as a high-growth opportunity with lots of share price appreciation. Instead, you get three basic values from owning this stock:

  1. A higher than average dividend yield.
  2. Earinings per share growth from a modest earnings increase and constantly reduced share count.
  3. In a long-term position, reinvested dividends and reduced share count increase the investment value. 

A company needs lots of cash to deliver on a value proposition that features high dividends and the capacity to reduce share count through share buybacks. The preferred way to generate that cash is through continuing operations, but a company of ExxonMobil's size is going to burn through billions of dollars in capital expenditures. So the most successful companies in the integrated oil and gas space are those that generate excess cash flow from operations after taking out capital expenditures. This is why that $2.6 billion figure is so important. That cash is basically what the company has at its immediate disposal to pay its dividend or buy back shares. 

ExxonMobil: The only place where the question is, "Is $2.6 billion enough?"
In just about every other context, $2.6 billion is a huge load of cash to spend. For ExxonMobil, though, it isn't as great as one would hope. The company shelled out more than $2.9 billion to pay dividends and buy back just over 30 million shares in the quarter, so that free cash flow generation simply wasn't enough. However, this might be a bit of a seasonal issue, as the company has generated more than enough cash so far this year to cover all of its obligations.

Source: ExxonMobil Earnings Presentation.

As long as the company can continue to crank out cash generation numbers like each year, ExxonMobil will do just fine for investors.

What a Fool believes
About this time last year, many shareholders were a bit frustrated that integrated oil and gas companies were pouring so much money back into their business and not necessarily looking to boost investor value. Those concerns are likely coming to an end, as the company has more than doubled its free cash flow from this time last year thanks to several major capital projects coming online and overall spending being reduced. As more of these major capital projects are completed, these numbers will likely continue to improve, and ExxonMobil investors probably won't be grumbling about getting their fair share anytime soon.