The third-quarter earnings season is done, at least unofficially, and here's the bottom line about it: mediocre.

Wall Street sees better results in the fourth quarter, but that's not a certainty. The first quarter of 2013 may be problematic as well.

It has been a trying quarter because earnings have mostly beaten estimates, but estimates were trimmed as time went on, according to Thomson Reuters I/B/E/S.In January, analysts were expecting companies in the Standard & Poor's 500 Index ($INX) to show 6.6% earnings growth in the third quarter over a year ago. With 466 companies reporting as of Thursday morning, earnings have shown no growth. That's a bit of an improvement. As of Oct. 1, analysts had expected earnings to fall 2.1% from a year ago.

Some 64.6% of companies' earnings per share have beaten estimates. In a typical quarter, 62% of companies beat estimates.

Energy and materials companies have seen the most pressure on earnings, largely because of falling commodity prices.

Revenue has been the big problem. Only 38.7% of S&P 500 companies have beaten sales estimates. Typically, 62% of companies beat revenue estimates.

A big weight on revenue has been a stronger dollar that has depressed the value of sales generated outside the United States, says Thomson Reuters analyst Gregory Harrison. Add to that a slower Chinese economy.

Telecommunications companies have reported better-than-expected​ revenue, perhaps because of the big growth coming in smart-phone usage. About 63% of companies in the sector beat revenue estimates.

Utilities have seen the least revenue growth. Only 10% of that group reported better-than-expected​ revenue.

You can see these issues at work in Thursday's earnings report from Wal-Mart (WMT). The retail colossus earned $1.08 a share, up 11.4% from a year ago. The earnings beat the Street estimate by a penny.

Revenue of $113.2 billion was up 3.4% from a year ago but missed the Street estimate by $1.8 billion. And the higher dollar cut reported revenue by $1.7 billion.

Wal-Mart's guidance was a bit weak, and the shares were down $2.61 to $68.70. The decline subtracted 20 points from the Dow Jones Industrial Average ($INDU), which was up 14 points to 12,585 at 1:54 p.m. ET after falling as many as 70 points early in the session.

Rival Target's (TGT) shares were up $1.35 to $62.73. It has little non-U.S. exposure yet. It will starting next year when it starts to open new stores in Canada. Earnings were 96 cents a share, including 15 cents for the sale of its credit-card business. Revenue was up 3.4% to $16.6 billion.

The moral of the story: Companies with than non-U.S. exposure in the quarter showed better results than multi-nationals that generate significant sales outside the United States.

Were companies stupid to look for growth in Europe and China? Of course not, Harrison said. China has been one of the great engines of growth in the last few years and may reclaim that role next year. And few people expected the European debt crisis to put the continent into what looks like a rolling recession that may take some time to overcome.

We say the earnings season is unofficially done because Wall Street looks at the earnings season as the period between when Alcoa (AA) reports (on Oct. 9 for the third quarter) and when Wal-Mart Stores (WMT) and Target (TGT) report.

There are big reports yet to come. Best Buy (BBY) Hewlett-Packard (HPQ), Salesforce.com (CRM) and Deere (DE) report next week. Costco Wholesale (COST) Oracle (ORCL) and Nike (NKE) report in December.

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