You'll need to find a way to make your spreadsheet accessible. You can build a website, which will require paying for a domain, hosting, site security, dealing with an internet transaction service, graphic design, content for the website, marketing your website, Search Engine Optimization, and all the other madness that comes with managing a site.
They are the ideal tools for companies who lack the financial resources and / or the staff required for generating spreadsheet solutions with specific programs. At present, the most requested types of ready-made spreadsheet solutions are "Spreadsheets for Small Business" and the subcategory "Spreadsheets for Actors".
Protection of formulae : How often have you forgotten to protect the cell contains the formula that took you hours to test and perfect. It takes one instance of honest human error, and that formula is gone.
All of these things pull you away from the thing you really want to do...which is to build and sell great spreadsheets. The best thing to do is use Excelville.com since they have web developers and internet marketing specialists to help get exposure for your spreadsheet.
examples of spreadsheet packages
spreadsheet templates for tracking