I've used addevent in both small business and large corporate environments, which makes it easy to use across multiple platforms (mobile and browser). The price point is also very reasonable compared with other services we are considering using. As mentioned above, this is easy to integrate into our CRM tool as well. There isn't much that could be improved here. If you're looking for something simple but powerful like iCal or Google Calendar integration, then Add Event may not fit your needs perfectly. Instead, look at more complex solutions such as FullContact's Integration Platform - this allows us to get granular control over data sources, fields, etc. For example, if you want to connect directly to Salesforce data via API rather than through their connector/integration platform, this can be done easily by implementing an appropriate REST endpoint within our system.