Google (NASDAQ:GOOG) blew away analysts’ expectations late Thursday, pushing the stock up more than 12% on Friday. On June 28, I suggested buying Google and since then it has risen 21%.

Even with Friday’s jump, with the company’s new Google+ social networking site growing in its invite-only stage and this strong report, it looks like a good time to buy Google shares  Here’s why:

• Great earnings reports.  In Thursday’s report, Google announced earnings of $8.76 a share on revenue of $9 billion – well above analysts’ expectations. Including this report, Google has beaten earnings expectations four out of the last six quarters. This ability to beat expectations fairly consistently, and by decent margins, is a good sign for Google’s stock price
• Out-earning its cost of capital. Google is earning well in excess of its cost of capital and that’s growing. How so? It produced positive EVA Momentum, which measures the change in “economic value added” (essentially, profit after deducting capital costs) divided by sales. In 2010, Google’s EVA momentum was 3%, based on 2009 revenue of $23.7 billion, and EVA that grew from $3.1 billion in 2009 to $3.9 billion in 2010 using a 9% weighted-average cost of capital.
• New Revenue Stream in Google+ and Continued Android Success.  Google+ already has 10 million members and more than 550,000 Android phones are being activated each day. With its new Chrome OS operating system just getting started on computers, Google is showing that it is much more than just a search engine.
• Fairly priced. Google’s price-to-earnings-to-growth ratio of 1.04 (where a PEG of 1.0 is fairly priced) means it is essentially fairly priced. Google has a price-to-earnings-ratio of 20.5, and its earnings per share are expected to grow 19.7% in 2012.

Google’s new CEO, Larry Page (one of the company’s co-founders) is showing early signs that he is going to rev up the company’s innovation engine. In the past, Google has had trouble introducing new services that people actually use and it has suffered plenty of employee attrition – often to Facebook.

If the second-quarter results turn out to be the first of many great reports, Google’s stock could soon power through its all-time high of $715 hit in December 2007.

Peter Cohan has no financial interest in the securities mentioned.