Many of the competitive research tools like SpyFu or SEMrush show historical ad copy. If you look at some of the biggest money terms (like hotel keywords & credit/insurance/financial product related searches) that should yield some ideas in terms of how things have shifted over time.
As the market has grown more saturated perhaps the difference between success & failure is far more in the landing page, keyword targeting & brand awareness than in the ad copy. Also there are now so many ways to adjust bidding (by keyword match type, country, metro, repeat visitors, look alike audiences, other demographic aspects, different bids for different device types, etc.).
For example, Amazon.com recently reduced affiliate payouts drastically
http://www.newspapergrl.com/amazon-changes-payouts-affiliates-no-longer-based-volumeand jumped into the Google product listing ads market. When they jumped into the PLA market they quickly outbid competitors on mobile
https://www.merkleinc.com/blog/amazon-focusing-mobile-google-product-listing-adsperhaps they could bid more on that device because their mobile click value is higher than it is for other merchants who lack their brand awareness.
Sometimes I chat with
http://timmcguiness.com & he talks about how AdWords keeps becoming more automated over time & has highly recommended using
http://www.optmyzr.com for automating AdWords management
Reply #6 on this thread
http://th3core.com/talk/traffic/the-future-of-seo-predictions-and-premonitions/ is quite good
For me, the issue that continues to be harder and harder with SEO is not ranking (that's easy)...it's getting the click. With Google making it less and less obvious what is an ad and what is organic search and the knowledge graph, I am almost ashamed to say that I've resorted to click bait type titles to get the clicks. There have been #1 rankings we've nailed that produced less than a 1% CTR, which was verified with PPC too. While the search levels given from Google are always off, we knew we were off when PPC clicks were through the roof with the same Title.
So...here are some things we did.
- Put the registered trademark symbol in the Title next to the site name. (even if you don't have a register trademark)
- Using "CONSUMER WARNING" at the beginning of the Description
- Warn about competitor advertising in PPC area. Make sure information is legit for the warning. Searches can easily find not just customer complaints, but past bankruptcy filings, government fines, etc.
Doing these clickbait options and constantly doing A/B split testing and tweaking the messaging, we increased the CTR by 6x.
