Is it about bolt-ons?.
On the Internet, bolt-on, perhaps inspired by add-on , is used to describe products and systems that can be quickly but securely attached to an existing Web site . The term most often describes some e-commerce solution for adding an online store to a Web site. A "bolt-on e-commerce solution" typically allows a Web site owner to create customized Web catalog pages, using a furnished template that includes a shopping cart approach for multiple item orders, and to have these pages hosted at the solution provider's server, where orders can be taken and reported to the Web site. Solution packages typically include the handling of credit-card applications and credit checking.
http://whatis.techtarget.com/definition/bolt-on