One of Apple's (NASDAQ:AAPL) most successful and long-running ad campaigns of the past decade was its famous "I'm a Mac" campaign, cheerfully poking fun at Microsoft (NASDAQ:MSFT) Windows in a lighthearted way so as not to appear too antagonizing.

Apple subtly undermined the rival operating system by calling out its biggest weaknesses. The campaign ran for a whole four years, a relatively long time in the world of advertising. Microsoft subsequently responded with a new "I'm a PC" campaign in an effort to spin the saying in a positive light.

That was all years ago, and Microsoft has now turned the tables on Apple. The software giant has released a new ad, but instead of personifying operating systems with comedians, Microsoft stacks up a pair of tablets.

The approach is very similar: Playfully call out the rival's weaknesses in a jocular fashion. Microsoft's live tiles update with information dynamically while the iPad's icons remain static. The iPad lacks PowerPoint, and can't multitask apps side by side. The iPad model shown also costs $250 more than the Windows 8 tablet displayed, the ASUS VivoTab Smart. These are all true of the selected comparison.

This comes shortly after another Microsoft ad poking at Apple's long-standing battle with Samsung. That spot pitches the Nokia Lumia 920 to the Apple and Samsung loyalists duking it out at a wedding while touching phones and talking to Siri. Microsoft's recent ads are clever, and a little less aggressive than Samsung's shots at the iPhone maker.

As rivals continue to prod it, Apple has opted to stick to the high ground and focus on its products. After a string of marketing flops, Apple went back to a reliable formula of emotional appeal combined with product demonstration, which is the same approach that Google has adopted. The search giant has also chosen not to target rivals directly in its ads, instead showcasing what its gadgets can do.

Microsoft's ad could easily prove to be a success from a marketing standpoint, borrowing from the same formula used against it so many years ago. Let's see if it translates into Windows 8 sales.