I like how easy their product makes it for you when sending out e-newsletters, because all of your contacts are already in there! If they could just implement some sort of system where one can see which individual has opened an email or clicked through rather than relying solely upon CTRs (click rate) would be great as well - but this isn't hard with conversionfly's software/systematized approach versus having someone do so manually. It also helps us keep track if we send too much information at once vs not enough info etc.. This was helpful since our last newsletter sent about 2 weeks ago had over 100 people unsubscribe from receiving emails within 48 hours due only time lapse between mailing date & actual deliverance being received by customers).