Fiverr has no ranking system... If your gig is showing on first page then it doesn't means that you will be on top forever... I observed that fiverr is working on rotation. In this process fiverr continuously rotating the gigs...
For example, if you search for "logo design" then you will see some results ofcourse but when you search again with same keyword then you will notice that most of the gigs removed for first page...
So... You just try to write good title, description and ofcourse a goood attractive gig image.
Now its fiver turn, he will definitely try to through impressions in your gig... If your gig could not impress the buyer for click then it will be your fault....
If you think i understand fiver wrong then please tell me where and what i said wrong... 🙂