Google Analytics - Absolute Unique Visitors query

We've recently installed Google Analytics on our intranet site which - obviously - is only available to internal staff. There are around 4000 members of staff in our place of work and so we can have an idea of the upper ranges of our "unique visitor" count.

For the period Mar 15, 2011 - Apr 14, 2011, there have been "10,307 Absolut开发者_如何学JAVAe Unique Visitors", averaging out at around 2000 - 2500 Absolute Unique Visitors hitting the site each day.

Is this metric telling me what I think it is? That is, in the period stated, 10,307 different people visited our intranet site. If so, how can this be, when we only have around 4000 staff?

Any help much appreciated.

Thanks

Unique visitors are tracked using cookies.

If each member of your staff uses two or three browsers (eg, Firefox and IE, or laptops, desktops, and smartphones), you'll get 10K unique visitors.

It could be that your organisation infrastructure forces cookies to be cleared after every session, or when users log out of their machines.

When cookies are cleared, a subsequent visit will be considered by a new visitor.

I would suggest taking a look at a user's repeat visits and ensure that the _utmz cookies does indeed persist.