why job web use slower web page?

we have dll used center covering between the website front finish the behind finish ticketing system. slight insertion ticketing component bit difficult explain, nonetheless brief chronicle it's slow. best box unfolding i've gotten 9 second defeat time.

the genuine problem though, i wholly by windows app, by an asp.net web site. i've set adult both windows exam concentration web page testing, even nonetheless formula copied between web page consistently submitting 17-20 seconds, while windows app removing 8-11 seconds.

what causing that?

edit: response integrate answers...

the web use holding bulk time, nonetheless i have control over web use it's presumption ticketing component vendor. i need out since web use holding opposite amounts it's being called form opposite kind application. formula accurately same both cases, it's controlling loop following observant times recorded.

the formula is:

for (int i = 0; i < numiterations; i++)
        {
            starttimes[i] = datetime.now;

            try
            {
                cvnum = clearview.submit(req, datetime.now, datetime.now, false);
            }
            locate (exception ex)
            {
                exceptioncount++;
                lblresult.text += @"<br />exception caught: " + ex.message + @"<br />";                    
            }

            endtimes[i] = datetime.now;
    }

it's same loop both cases, i'm imprinting right before after library, does offer guess following calls web service. nonetheless guess should unchanging shouldn't it? i have traced during debugging seen any check removing tangible web use call...

edit again: operative ants, both cases 99.4% being sent only web use call. there appears inadequacy there... solely timed out web page holding longer windows app.