Whenever you get people to vote on a list of tasks, clear trends will quickly emerge... Typically, in surveying 100 tasks, the top 5 tasks will get an average of 25% of the vote, with the bottom 50 tasks also getting 25%. In other words, the top 5 tasks get as much of the vote as the bottom 50.If you've not come across this before, I recommend you investigate further. I've found that conducting a survey like Gerry's can be a great compliment to analysis of your webstats.
Top tasks identification method explained - article by Gerry McGovern
Long version: Web surveys are broken: how to fix them (PDF: 2 MB)