For pure data analysis, the spreadsheet is, indeed, king. To a point...Despite all of these extremely powerful features, the spreadsheet has limitations, which tend to manifest when you least expect it. Often, Murphy's Law applies and the spreadsheet falls over when you are right in the middle of a major undertaking, like month-end or meeting a tight deadline.
You can build a reputation as an expert spreadsheet developer. This certainly doesn't hurt the resume. Using Excelville.com to sell spreadsheets allows you to set up a profile with your work, biography, and other info that certainly makes for good conversation material during interviews.
Financial templates are highly complex and they deal with very large and advanced calculations. These spreadsheets are used in mortgage, loans, and property investments and so on.
The spreadsheet templates used for business purpose are also complex and these templates are used in stores and other business related affiliates. Profit and loss are mostly dealt with these spreadsheets. Invoice and other deposit related calculations also can be dealt with these spreadsheets.
examples of spreadsheet packages
what is a spreadsheet used for
spreadsheet templates for business