My first thought when I read this post was “did you try someone besides MailChimp?” My understanding is that they’re not really a market leader and that there are competing solutions that are either better, cheaper, or both.
That said I think this is an interesting niche to be in, because I think there are some customers out there who don’t need the technical hand-holding of other marketing platforms.
How do you define market leader? In 2021 they had 14 million paying customers and a market share of 72 percent. If that’s not a market leading position, I don’t know what is. I don’t favor them, it’s a real pain sometimes, but they operate a tanker, not a speed boat.
I defined that poorly. What I mean is that they're a declining incumbent who doesn't have the best product or pricing.
While they are the market leader in marketshare, they're losing marketshare rapidly. [1]
Now that they're owned by Intuit, I only expect the product to get worse.
OP's product seems to allow you to get more specific about segmentation, which is something that a rapidly growing MailChimp competitor Klaviyo seems to excel at, as an example. [2]
I know this is probably no more than a side project for OP, but if I was in their shoes I probably wouldn't have started building this kind of thing myself if I hadn't tried at least 3 other alternatives. Email marketing/marketing automation is a very deep specialty, so I think you have to really be sure that there's nothing suitable off the shelf before you wade into building your own solution. I feel like it's not much different than building your own database for your application. I would want to be really sure that there isn't one already out there that fits my needs before building my own.
That said I think this is an interesting niche to be in, because I think there are some customers out there who don’t need the technical hand-holding of other marketing platforms.