Simply the best! We switched from omnisend and find it much easier to work with. Should have gone with my gut and implemented Klaviyo in the first place. Super responsive support as well.

Lots of customizations, awesome customer support ;) So far best marketing app that I've ever found ;)

Great campaign flow interface and integrates well with Shopify. Support is pretty decent. Would recommend.

Great platform that is straight forward to use. I have found their customer support very helpful and quick to respond.

We were using this app for a month and the setup for re-targeting emails was easy enough and it seemed to be working, but was surprised to sign into the app today after a couple days of not signing into it only to find that it had completely disconnected sometime in the last couple of days (so our potential customers weren't sent emails), so I have the option to set it all up again and hope it doesn't happen again, or go with a different app..I think we all know which is the safer choice. But using the app at least was a good enough experience up until that point.

Love the App!! You have such a large variety of options and the concept is really sophisticated. The help guide is really useful and the customer support is always great!

OCT 31 Update:
I just downgraded this app to a 1 because of their customer service. While is it a really good tool for those of us selling physical products on an ecommerce site, It has by far the absolute worst Customer Service of any CRM app I have used in the last 15 years.
Sometimes their automated Flows do not work. If that happens on a weekend, like it is now, then you have basically no customer support until Monday and you have lost sales for a weekend email campaign which will not send.
So what if it happens over BFCM? There will probably be no support from Wednesday afternoon till Monday morning. While it's great this company cares about their employees, the support they offer to their customers is really the worst I have ever encountered in this particular niche. When it comes to reviewing an app like this there are 2 things to consider… the app itself and the customer service. Also, the experience of the reviewer using the app. CRM apps always have a steep learning curve and so at the beginning support is needed to help us fill in the gaps where documentation is lacking. I have been using this app for about 2 years and participated in the Beta testing of their drag and drop Flows. I know my way around it but still need some help from time to time. I am writing this review so you know what are getting into before you make a purchase decision..
Like most apps, it has its quirks and that's all cool. You just need to learn them and just about every CRM app has a steep learning curve to overcome at the beginning so a good and timely support team is really critical. The app itself is a really great value. To capture all that value good customer service is needed and that is where Klaviyo falls short. In fact, over my last 20 years on ecommerce, this company’s customer service is, in my experience, one of the worst I have ever experienced. First off, they only have chat support and then... the chat hours are limited and the actual quality of the support is hit or miss. Be prepared to wait up to 45 minutes or longer to even get to a support rep. Although, to be fair, wait times, in my experience, have been as quick as 15 or 20 minutes. They do actively support the ecommerce community with fresh, innovative ideas and create videos which are totally awesome and very relevant. This is a great platform if they only had decent customer service.
I gave the rating of 2 only because of the app itself. It’s a good app with lousy support.
If you do decide to purchase this app then just know that the customer service is pretty terrible and that I am not just a newbie to this app but have been using it for about 2 years.

I've heard nothing but good things about this platform, however, after attempting to use their E-mail system for a month it's by far the WORST software and WORST customer service I have experienced in my life. Not to mention incredibly underhanded tactics by their development team to make it infuriatingly difficult to manage your customers/profiles in their system! They clearly do this so that it's hard to remove contacts ... because they charge you based on the number of subscribers you have. ie) No multiple select to remove profiles. Their profile page doesn't even auto-scroll to refresh more profiles!!! You have to manually search and click 3x into someone's profile to delete it, or create a segment which is also wonky with not enough options to delete (bots). Their customer service is ABYSMAL. If you get an e-mail back at all it may take days or weeks. Then to a detailed question you will receive a single line non-sensical answer. As soon as I can find ANY alternative I'm gone. WORST platform period.

Just started with first campaign, 5 star is for Designing and tamplate is like plug and play automation still need to try will update later on this.

very poor support. we send them emails but there is no reply from their side. we regret adding there app.