Using a CRM today is critical, whatever the size of your company is. An excel sheet simply doesn't get the job done. (Remember how long it takes to 'merge' several excel sheets when sending christmas cards?). Salesforce is the american leader of the market: robust, complex, expensive and delivered in the cloud with an army of consultants ready to help you with the configuration. We've been using it for 10 years. Zoho is the indian competitor: intuitive, low cost, with a stunning free "Chat" with Zoho experts. You could call it the 'Wix' of CRM! Zoho CRM is also connected with many other apps. Difficult choice. Then comes the story of data protection and compliance. Vast subject! In Luxembourg for example, both softwares are not allowed by CSSF for financial companies. Good luck if you need to code your own CRM: it is like trying win an oscar with a self-made i-phone movie!