Google Analytics Expert Needed For Wild Swings In Conversions

Hi, I need a Google analytics expert to help me figure out the wild swings in conversions on my site. From week to week, sales vary wildly even though traffic stays the same for the most part. I need someone to review my stats over the past few months and help me figure out the cause for the change. I need some solid answers as to what the difference between "bad" days and "good" days are. PLEASE NOTE: I will only consider coders who include their experience in Google Analytics. Please include the word "plum" in your bid to confirm you've read this. Thanks in advance!