Crossing the Chasm: Geoffrey A. Moore https://en.wikipedia.org/wiki/Crossing_the_Chasm

Basically, there's a lot more to sales than just "generate leads." You need to pick a "right-sized" market, tailor the product to the market (but not too much, so you can go after other markets,) and then as you grow, move to bigger markets.

The markets you go after when your company is small are very different than when your company is established. Furthermore, small differences in your product are critical: A tiny feature or option might be critical in a tiny niche that you need to get started; but a completely different feature or option is needed when you're able to target a larger audience.