Right now custom fields are only allowed for contacts. Adding custom fields saves a lot of time for email allowing for dynamic insertion. Have custom fields that can be added that show in the configure page of products to set the email name, the topic area, the related services links etc. This would allow you to add these variables into the emails or other parts of the product pages etc. and save a ton of time by using the same email templates for each product sequenc and have the appropriate info inserted dynamically.