I have found all my google shopping campaigns eventually end up serving a one or two items representing 75% or so of all impressions. The items get served on terms that make little sense at all and not connected to the product itself. Examples: a t-shirt with an image of mountains and camping had the term hand drawn n the description. that item became 50% of my campaign on search terms like drawing, hand-drawn, how to draw, draw a mountain scene by hand. another sticker had a bunch of fish on it and it took over the campaign on terms of mahi mahi. A patch with a dinosaur image served on 'are dinosaurs real' and 'dinosaur dinosaur dinosaur' served 80% out of 1000 products. It happens on ad groups with few or many products. one ad group will beat out others and they stop serving. I have moved them to new campaigns and it starts again. when i call support they only advise to disable the offending product and say it should not happen again :(
Current setup: I have selected the "do not optimize rotate ads indefinably" and Manual CPC. I have edited descriptions, titles and meta data to no effect. The only thing that works is to kill off the failed product and then another takes its place within a month. I have all products of a related type in their own ad group. some ad groups have 1000 products like 'funny stickers'.
I would like a more even serving of ads and have the serving make more sense.
Any advice on what I'm am doing wrong to make the serving algorithm fail so hard? Any other settings i should consider? My current Idea is to somehow build a script in my feed generator that 'out of stock' 20% of items every few days to help the algorithm from target locking- is something like that a solution?
