I've used datarooms in the past as an investor, and as someone raising capital.
Several options for you:
If you want to be REALLY scrappy, you can use Docsend + Google Sheets + Dropbox as a way for you to provide links to all documents in one place (Google Sheets), have all views be tracked (Docsend), and all storage in one place (Dropbox).
For the investor, it's a way to have all diligence documents in one place (term sheet, model, customer data, analysis, etc). They will likely continue to make additional requests for raw data and analyses as the diligence process progresses.
For the entrepreneur, you want to be able to track who is viewing documents, when they viewed the docs, how often they view the docs, etc. It's helpful for you because it gives you a sense for what is important. For your key documents (model, financials, user behavior), you want to take a spin through your raw data first, so you can provide insight into the data before the investor just takes a blind stab at everything.
Hope this helps.