meaning of this content

[user20]

Hi
I am not native English. I am reading an article, But some part are too difficult to understand.
here is the content:
"if your campaign's prospecting for fresh leads, you need one type of data—companies you haven't approached recently—whereas if you're selling upgrades, only your existing customers need apply.if your campaign's prospecting for fresh leads, you need one type of data—companies you haven't approached recently—whereas if you're selling upgrades, only your existing customers need apply."

[Tarheel]

I have made a couple of necessary changes.

"If your company's prospecting for fresh leads, you need one type of data—companies you haven't approached recently—whereas if you're selling upgrades, only your existing customers need apply.

If your company is looking for fresh leads (potential new customers) then you are looking for one type of data (which is companies you haven't approached lately). However, if you are selling upgrades you are only interested in talking to existing customers.