IBM extended its e-commerce technology buying spree today as it announced plans to acquire Tealeaf Technology Inc., whose software analyzes consumer behavior on Internet and mobile sites.

While not disclosing the purchase price, IBM says it has invested $3 billion in its Smarter Commerce initiative designed to address client companies’ technology needs in the digital age. Its investments include its $440 million acquisition of DemandTec, which analyzes consumer buying behavior, announced in December 2011; the 2010 deal to buy web analytics vendor Coremetrics for an undisclosed price, and the August 2010 purchase of online marketing firm Unica for $480 million.

Tealeaf serves 450 clients, IBM says. Among them are 18 retailers in the Internet Retailer Top 500 Guide, including Sears Holdings Corp., No. 7 in the Guide, Best Buy (No. 11), HP Home & Home Office Store (No. 19) and HSN Inc. (No. 26).

“Marketers must continuously deliver a better customer experience on both the Web and mobile devices to meet the expectations of today’s empowered consumers,” says Craig Hayman, general manager of Industry Solutions at IBM. “With these new capabilities from Tealeaf, we can not only provide chief marketing officers and other marketing leaders the qualitative insights into how customers actually experience their brands, but show them how to react in real time across marketing, sales and service.”

Tealeaf’s software was developed by SAP AG, the German provider of business software. SAP spun off Tealeaf in 1999. Based in San Francisco, privately held Tealeaf has been funded by venture capital firms, including Foundation Capital, Matrix Partners and Bay Partners.

The deal is the latest example of major technology companies snapping up companies with e-commerce expertise. Oracle Corp. in the last two years has purchased e-commerce software provider ATG, site search specialist Endeca, contact center technology provider RightNow Technologies and personalization vendor FatWire Software. And Adobe Systems Inc. acquired web analytics vendor Omniture in 2009 and search marketing firm Efficient Frontier last year.