Using an excel sheet to manage and ultimately sell your costumers is like trying to hand out pamphlets in the middle of a crowded room, inefficient, inconvenient, and often time consuming.
Customer Relationship Management (CRM) is a tool to help improve the communication you have with your prospects leading to a better, long lasting relationship. Having the ability to segment your prospects based on characteristics, needs and preferences will make your sales process seamless and effective. You will be able track your sales initiatives more accurately and have a better idea of what to do to reach your goals, things an Excel sheet simply cannot do.
A CRM platform will also enable you to have more control and visibility of all your information anywhere you go, allowing you to reach relevant and up to date information from your web or mobile device.