Alliance Data Systems Corp. has agreed to purchase data firm Abacus from DoubleClick for $435 million in cash and will incorporate into its Epsilon brand, ClickZ reports. Pending regulatory approval, the acquisition is planned to close in 1Q07.

Abacus's more than 500 staffers, including senior execs, will now work for Epsilon, though Abacus will retain its name. Epsilon's marketing-related data services, especially in the retail sector, will get a boost from the acquisition while allowing Abacus to connect with Epsilon's non-retail clients in the financial, pharmaceutical, travel and other verticals.

The $435 million price is one-fourth the $1.7 billion that DoubleClick paid for Abacus in 1999, writes Reuters. The online marketing firm was hoping at the time to mine data to predict shoppers' behavior - but quickly became the focus of concerns about online privacy. In February, Alliance Data bought DoubleClick's Email Solutions unit for $90 million.

Abacus' services are used by over 1,500 multi-channel catalog companies, retail firms, online merchants, and B2B clients such as Brookstone, Patagonia and Sur La Table. It allows its co-op member clients (primarily catalogers) to access aggregated data from the transactional database to help predict future buying behavior and design marketing campaigns.