Seattle-based Zillow has acquired real estate listing creation and distribution firm Postlets, the firm said late this morning. Financial terms of the deal were not disclosed. Zillow said that the founders of Postlets, Asher Matsuda and Raymond Chen, have joined the Zillow team. Matsuda and Chen started the firm in 2005 as a side project. Zillow said Postlets now has over 500,000 registered users.