We studied when and how people will use a customization tool that helps users offload information indexing to the external environment to augment finding and re-finding of information in a computer desktop environment. An experiment was conducted to study how the cost and benefit of customization may influence when and how participants customize, and how the customization may help them find and re-find information. Results showed that participants were sensitive to the cost and benefit of customization. In general, participants performed more customization when the cost was low and when the benefit was high. Customization was also found to influence their information indexing strategy. Implications to design of customization tools for information indexing were discussed.