Member record keeping is often related to different points in time so having a summary count of members for the master lists, groups, and mailing results would really help make user's lives easier.
For example, in the Communications function, there's an array of the people that opened a message and other activities. In the member records list, there's a column for the last time people visited the website. Having subtotals on all various activities would help us better understand how members are interacting with our communications and website usage.