It's become the heart of our contact management system - it's low cost, simple to use and high impact for us. We are using a version that allows for unlimited employees, 50,000 Highrise contacts and 100 Gb or file storage. This means to us that this is scalable and sufficient for the foreseeable future. By using some other apps we can add some things that we need that aren't built into the product. We use infusionsoft but not as a contact manager for clients. When a contact in infusionsoft reaches a certain stage and we get more "hands on", we use Zapier to setup the contact in Highrise and create an embryonic deal. We like Mailchimp for email newsletters and Mailchimp syncs nicely with Highrise. Finally we use SalesClic to give us a more refined sales pipeline.