Each year, International Business Machines Corp. (NYSE:IBM) spends about $6 billion on R&D. It not only allows the company to launch better products -- but is also a source of licensing revenues. And the occasional lawsuit, such as the one filed against Amazon.com. The amount? Like most of these kinds of suits, it is unspecified. IBM's suit covers five patents, which cover things like storage, customer recommendations and other common features that any e-commerce company would provide.

Interestingly enough, IBM filed its case in Texas, which tends to be favorable to patent-holders. But, one thing is certain: patent litigation is time-consuming. So, unless there is a settlement (which does not seem like something Amazon.com likes to do), expect this case to continue for several years.

And, as seen with the stock price of Amazon.com, investors seem blissfully unconcerned. The stock is up this morning after the news by 24 cents to $32.81.

Tom Taulli is the author of various books, including the Complete M&A Handbook and operates InvestorOffering.com.