This last point in my opinion is ONE major benefit you must seek to extract, if you choose to engage the services of a developer. S/he should be able to help you develop (in_house) expertise needed to maintain the application AFTER s/he is gone. If you fail to ensure this, all your cost_savings from using the application might end up being spent paying the developer to maintain the application over time in the future!
This article is meant for those individuals/businesses who sometimes experience a need to use their spreadsheets in the (somewhat "impersonal"?) manner described above, to get the results they want. That need would often arise out of their lack of requisite skills to get the spreadsheet to behave the way they want _ or limited time to devote towards incorporating necessary automation to make it do so.
Spreadsheet Automation Facilitates EFFORTLESS Data Handling, Analysis & Report Generation! Sometimes people don't really care about learning(or using) all the "cool' advanced functions, formulas and techniques in the spreadsheet application they use for their work. They just want to punch in their relevant raw data _ at any time _ and immediately see the computed results generated by the spreadsheet in a manner that can facilitate their important decision making.
One Possible Application: Plotting a pie chart based on income contributions from all your products and services(daily, weekly or monthly), and reviewing the automatically computed percentages/visual pie slices, can give very illuminating insight.