We’re Looking for Insight Into Why We Get the Most Leads On Fridays

So our web analytics consistently show a decline in unique visitors on Fridays, but on a month to month basis, Fridays drive the most leads verse any other day of the week for our web design firm. Why is that? Is everyone so tired of putting out fires all week that by Friday all they want to do is some browsing on the web? Or do they finally get a few minutes to themselves to get to that 'to do' on their list of finding a new interactive agency? Or is Friday subconsciously the most creative day (and fun) day of the week? Any insight would be great!