Why will my 2005 Jeep Grand Cherokee not start?

For the last month my car has had problems
starting. I took it to a local place to have the battery
and alternator checked. Both of those were running
perfect. So we narrowed it down to the starter. I
had the starter replaced about a week ago and it
has started up every time until now 7 days later.
There is no crank, just one click and it sounds as if
it just goes dead after me trying. Hoping that
someone could provide me some advice/solution to
what this problem could possibly be?