Monetate, a Conshohocken-based company whose software personalizes online shopping for customers, announced Thursday that it is being acquired by Kibo, a Dallas-based rival.

Terms of the deal were not disclosed. But investors who had passed on backing Monetate noted that its sale to a private company only about twice its size showed Monetate was past its days as a high-flying flagship of Philadelphia’s small fleet of software development firms for the retailing industry.

Buyer Kibo is owned by Vista Equity Partners, a $50 billion (invested assets) tech holding firm.

Monetate will continue to operate as an independent brand with its staff of 130, mostly at its headquarters, Kibo officials said in a statement. Among Monetate’s largest clients are QVC, Timberland, Patagonia, and the North Face. It also serves J. Crew, Hot Topic, and Waitrose & Partners, a chain of British supermarkets, among others.

The acquisition ends what were once more ambitious hopes. Monetate, founded in 2008 by David Brussin and David Bookspan, had raised about $46 million in funding from investors including Philadelphia-based First Round Capital and Robin Hood Ventures.

Its head office was moved to New York City after Stephen Hopkins was hired to replace past CEO Lucinda Duncalfe last year, though most staff remained in Pennsylvania. The firm also has offices in Palo Alto, Calif., and London.

Kibo, which employs about 265 people, provides cloud-based software for online commerce. In February, it acquired Certona, a recommendation engine that also uses AI to streamline e-commerce sales. Kibo’s client base includes about 600 business-to-business and consumer retailers and brands, according to the company.

“The opportunity to become part of a larger commerce platform with complementary products is exciting for both our clients and employees,” said Monetate CEO Stephen R. Collins in a statement.

Kibo said that the acquisition of Monetate extends what Certona can sell, and that the companies’ products were complementary for retail clients.

“Monetate brings some fantastic capabilities that will be a great benefit to our clients ... site-wide A/B testing, content personalization, and their self-serve UI [user interface], just to name a few,” Kibo management said in a statement. “That said, we wouldn’t acquire a technology that didn’t have a proven user base.”

David Post, CEO of Kibo, will continue to lead the combined organization.