Whilst I agree that sales do go in cycles, my shop has been trending upwards since I opened it 4 years ago.

Some months can be a bit weird - for example in the middle of March I was down 40% compared to the same time last year, but then suddenly I had a rush of sales in the last 8 days and ended the month almost 20% above last years figures.

I do have 2 other online stores on Etsy which I opened up about 3 years and 1 year ago respectively. Their income stream definitely helps to add to my overall gross annual figures. The diversity has definitely helped.

I'm not going to retire anytime soon, but collectively between the 3 stores I do ok.