Has anyone here successfully taken over their own Amazon PPC for their brand?

I’m about 18 months into selling on Amazon. Right now I have 1 SKU live, I’m launching my second now, and planning a third in about 3 months.

I also have a pretty solid brand presence off Amazon, and I’m starting to grow into retail as well.

The challenge is that I still have a full-time job, so this business is very much a side-of-desk operation for now, although the goal is to eventually do it full-time.

Here’s where my numbers are at:

• YTD ACOS: 46%
• YTD TACOS: 30%
• Last 30 days ACOS: 37%
• Last 30 days TACOS: 26%
• February ACOS: 51%
• January ACOS: 39.5%

I’m currently using an agency, and they’re doing a good job overall. Their fee is about 5–6% of ad revenue.

I’m trying to decide whether it’s worth investing the time to really learn PPC and manage it myself, or whether I’m better off keeping the agency and focusing my time on growing the business.

Would love to hear from anyone who’s been in a similar position. Did taking PPC in-house save you money and improve performance, or did it just become a huge time drain?