Size limitation : When a spreadsheet is first constructed and tested, the size tends to be small. However, as the spreadsheet grows with more and more data, it start slowing down, until it reaches that point where your feet go to sleep while you waiting for the re-calculation to finish.
"Spreadsheets for Small Business" is a complete package of ready-made spreadsheets that optimizes and facilitates a series of business processes such as sales exec commission tracking, calculating business expenses and planning budgets. The "Spreadsheet for Small Business" package incorporates valuable programmed spreadsheets such as "Small Business Expense Spreadsheet" - provides accountants and tax-preparers with a complete report on relevant business expenses; "Producer's Budget" - helps users to establish budgets and keep track of their spending; "Monthly Personal Budget" - designed to track daily, weekly and monthly spending for individuals.
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.
One user at a time : In the instance where there are a number of people required to work on a spreadsheet, they can only access it when no-one else is working on it.