Scaling sales is a very different thing from getting sales, and I'd argue you won't know how to scale until you find a channel that works but is not cost effective. Otherwise you're essentially shooting blind, but at scale, which doesn't hit much but uses a lot of ammo.
I'm thinking more from the low-touch, low-margin perspective. If you are trying to make money with ads, calling 70 people to get 70 ad views is a terrible ROI no matter how persuasive you are. If you're selling a subscription SaaS product and expecting a lifetime value in the thousands per customer, then cold calling is a pretty decent way to bootstrap.
