About Office 365:
https://support.office.com/en-us/art...D-4070D2413AA7

http://www.zdnet.com/article/small-b...65-fine-print/

OK, I've reached the limit of My Office 365 knowledge

Access or Excel (PC version)
Excel won't be able to handle the data from 1000 campaigns, not to your satisfaction anyway.
Access will laugh at a measly 1000.

Let's assume that you are going to design the project around Access from the Start. The main change is that Access takes the place of all the Account Logs. Program Access to Average each Active Accounts last three days average and place that data into another Table, Historical Performance. Set up the Cycle Book, Daily Overview sheet, to ask Access for Today's data from the Historical Performance table. This means the one sheet in the Cycle Book has up to 1000 Rows of data to work on, not 1000 sheets. Perform the analysis on another sheet in the same book.

Don't ever imagine that jumping straight to design or coding of a project will be faster than planning the whole project first. I call those projects "Organically Grown" and they wind up as organized as a plate of spaghetti.

Here are some words of wisdom by the Project Manager for Excel 5 (and VBA?) Home Page
The Process of Designing a Product
Painless Functional Specifications - Part 1: Why Bother?

If you like his style, Read on:
Designing for People Who Have Better Things To Do With Their Lives - Part 1