The best replacement for vertical response is constant contact.

The best alternatives to vertical response are rated as following:
★★★★★  constant contact
★★★  mailchimp
★★  getresponse
★  campaign monitor
★  aweber
★  exacttarget
  icontact
  mail chimp

Your alternative for vertical response is not listed? Suggest!
Speaking about vertical response, one probably shouldn't forget about salesforce.

Other search terms related to vertical response and their ratings are:
★★★★★ salesforce
You have in mind a companion for vertical response and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of vertical response in all years. Click on graph for more.
vertical response
constant contact
mailchimp