Many organizations ask us to compare VerticalResponse to Soapbox Mailer with respect to the integration with Salesforce. Here's a short overview of the differences between the two products.
Data Storage Impact
Vertical Response: stores all email recipient activity, such as opens and clicks, in two custom objects (VR Email History Contact and VR Email History Lead), which takes 2KB of storage space per email per recipient. 20,000 email activity history entries will take up 40MB of storage space.
Soapbox Mailer: stores all email recipient activity in the standard Campaign Member object, which takes 1KB of storage space per email per recipient. 20,000 email activity history entries will take up 20MB of storage space.
Vertical Response: Salesforce users can only see email campaigns they've created with their own Salesforce user account, and can only see email campaign data in Salesforce reports that are from their own campaigns. This includes lists, templates, campaigns, stats, etc.
Soapbox Mailer: Salesforce users can see all email campaigns, depending on the permissions set by the Salesforce administrator, and can see all email campaign data in Salesforce reports depending on these permissions set by the Salesforce administrator.
Vertical Response: There is no way to allow the email recipient to request an unsubscribe action from an email list, and instead, any such action is recorded as a global opt-out.
Soapbox Mailer: Email recipients are able to signal their request to unsubscribe from an email list without being marked as a global opt-out request.