If you have a landing page that you’re sending AdWords traffic to, you should include relevant (and even better: relevant & unique) images with relevant captions to your landing page.
Google likes that and it will be a plus for your quality score. You also want to give these images relevant filenames. So if you are selling wooden toys, then you want to have images of wooden toys and name them accordingly.
Now, this one is important: do not name unrelevant images with relevant names. Sooner or later Google will figure that out and it will punish you with high click prices and low quality score!
In the end, it’s about providing Google’s users with the best experience - and it’s a fact that people like pictures, not long blocks of text. So, whatever Google tells you to do, do it their way if you want to get a piece of the online pie, because Google is the ultimate 800 pound gorilla online, and nothings gonna change that in the near future.
