We have two pipelines in our PD - New Business and Repeat Business. 

And it's easy to track the Source of new business as a custom field when you get a new lead. But it's hard to find the original source of the leads after it moves to the Repeat Business Pipelines when you have multiple people involved and multiple products are purchased.

For us, the Source is Google Ads, SEO, LinkedIn etc channels where the leads come from.

As there is no conditional logic in the custom fields, we have to feed the data for both pipelines.

Do you ignore the original source of the lead once it becomes a repeat business or keeps the record for reporting?

I think it would be good to see which channel has brought what level of revenue later but it's becoming hard to keep the data clean. 

Not sure if it can be automated or there are other better ways.

Thanks in advance.