I think I’ve reached the “Etsy is no longer enough” stage

Etsy has been my main sales channel for a while now, and thankfully, things have been going pretty well.

But looking at my numbers recently, I’ve started thinking more seriously about expanding to other platforms.

I’m considering Shopify + Amazon, but here’s the funny part:
I know Etsy pretty well at this point… and honestly, almost nothing about the other two.

When it comes to the operational side, managing my stores, listings, orders, fulfillment, and everything from one dashboard. I already have a tool in place for that. What I’m really looking for is advice from sellers who have actually scaled from Etsy to other platforms.

So I’d love to hear from sellers who have already made the jump.

If I already have products that are selling well on Etsy:

Can I basically take the same products/catalog to Shopify?
What about Amazon — can the same POD products work there?
Which one would you recommend starting with: Shopify or Amazon?
How different are product research, SEO and customer behavior compared with Etsy?

I’m especially curious about Etsy → Amazon. I’ve heard very mixed opinions on whether a product that works well on Etsy will actually work on Amazon.

For those of you who have expanded beyond Etsy:

What do you wish you knew before starting?

I’d really appreciate hearing your experience, even if you think I’m approaching this the wrong way

Thanks in advance!