Let me explain. It's hard to make money with a business that has only one product to sell. It simple costs too much money to ACQUIRE a customer. The big profit is made in getting REPEAT SALES from a customer. The person who likes your first product is a very good candidate for your second product.
So if you don't have a second product, you've lost out on an opportunity. Your business struggles rather than flourishes.
If your "first" product is a perfume that took you a year to develop, can you afford to wait another year until you have a second perfume? Certainly this would slow down the growth of your business but, perhaps, you can find OTHER products that COMPLIMENT your perfume.
The classic line extension for a perfume is the soap, bath oil, linen spray, candle routine. But this is tricky as, not only does it involve a significant cash investment, it also requires a good deal of technical skill -- the skill of a cosmetic chemist perhaps. Going down this path may not be appealing to you.
But there are alternatives: scarves, costume jewelry, (somebody else's) soap and bath products -- items that can be purchased through normal, wholesale, "gift boutique" channels. You won't get the markup you might like on these products but you can buy them in small quantities and these other products -- if well selected -- can put the icing on your cake.
You might have a better idea for a "second" product -- but those "second products" will speed your way to business success.