I assmue the search results is based on keywords, downloads and app ratings. Please correct me if I am wrong. Also is there any other criterai for the app to be listed on top of the search results? Is there any advertising program where app can be listed as featured etc?.
Is there a way to get App on top during search
There's nothing you can do to be featured other than produce a great app -- the featured apps are picked by Apple. Also, nobody knows for sure what factors affect search order ranking the most except Apple (although there is a lot of speculation).