u/spicemelange13

Two weeks ago I used my own tool's MCP connection to run a study via Claude, looking into Gemini Flash models (2.5 and 3.5) and their overlap with Google Search. Here's the original https://www.reddit.com/r/GenerativeSEOstrategy/comments/1ugjgir/62_of_urls_cited_in_gemini_25_flash_are_gone_35/

Variance is within the nature of AI models, so I ran it again 12 days later - same 50 prompts about hypothetical sports outcomes, same models and Google Search Top 15 tracking.

Let's start with what didn't change:

- ESPN 0 citations. Across all 4 runs (that's 1,195 citations across 2 model versions in two different runs)

- Again, for contrast: ESPN ranking Top 3 in 23 out of 50 searches in both runs on Google Search. It's 0 on Gemini across both models.

- Gemini vs. Google Organic SERP overlap is minimal. The most recent same-day comparison shows 11% overlap. The original finding was 19%.

- Wikipedia and YouTube are the only truly stable citation sources across all 4 runs. 3.5 Flash cited Wikipedia in 35-40 prompts and YouTube in 21-24 prompts - consistently, across both time snapshots.

What did change:

- Over just 10 days, Gemini 3.5 Flash replaced 69% of its exact URL citations.

- Gemini 2.5 Flash replaced 74% of its citations over 11 days. Betting sites citations share in 2.5 Flash went up - from ~14% to ~18%.

- Google retained 41% of the same URLs.

- Gemini is actively swapping in fresh content. Citations like the LeBron Lakers exit (published June 30), the Giannis trade (June 26), Usyk vacating his titles (June 26), and the Verstappen-McLaren rumour (June 26) all appeared as new citations that weren't there 10 days earlier.

- At the same time, pre-tournament odds pages, fixture previews, and prediction trackers quietly disappeared. I could notice Gemini dropped the stale, picked up the breaking. Google's index hadn't caught up with that as fast.

I can't stress enough for SEOs who look into AI Search to start treating GEO (or whatever terminology you prefer to use) as a new channel that requires a different approach, different analysis methodology and different metrics.

For ESPN, "Good SEO" IS NOT equalling "Good GEO" as recently stated by one of the Google's execs. Also, this is not just "SEO with extra layers" as stated by big part of the prominent voices on LinkedIn.

https://preview.redd.it/8zxrhbiluoah1.jpg?width=1672&format=pjpg&auto=webp&s=85fe70399ef7eb7724b0368c9d0fd26f199ff7bc

I analyzed hypothetical sports prompts across Google Gemini 2.5 and 3.5 Flash to measure betting site citations. I was initially surprised to see a large amount of betting sites suggested by 2.5, but ended up finding something else completely :)

- Gemini 3.5 Flash was more willing to answer hypothetical sports questions: 49/50 vs. 28/50 (2.5 Flash).

- Gemini 3.5 Flash cited slightly more URLs on average - 8.1 vs. 7.7 at 2.5 Flash (not statistically significant).

- 82% of cited URLs are not mentioned in Google's SERP Top 15 (organic). This is consistent between both 2.5 and 3.5 models. And 55-62% (depending on model) don't even share a domain with any URLs ranking in the Top 15.

- Only 38% of domains cited by Gemini 2.5 Flash were present in Gemini 3.5 answers. This is a massive shift from one model to another.

- Wikipedia and YouTube are the most stable citation sources (appearing in 14 and 7 prompts respectively). The 3.5 model is citing both sources considerably more often than 2.5.

- Gemini 2.5 is surprisingly leaning towards betting sites (14% of answers). This changed with 3.5 - only 6% of citations, more or less corresponding with organic (7%).

- In 2.5, betting clustered by sport. Football tournament queries were ~70% betting citations, rugby ~80%. The model reached for odds specifically where outright markets exist.

- More specifically - 2.5's refusals tracked betting markets. It declined most future tournaments (Champions League, La Liga, NBA, F1 titles) but answered the ones with live outright markets - and answered those with betting sites.

- I ran the test against ESPN (homepage URL) - it was ranked consistently in Google's Organic Top 15 for many queries. ESPN appeared in 0 citations by both 2.5 and 3.5 Flash Gemini models.

The biggest insight in my opinion is the model variance. The difference between Gemini 2.5 and 3.5 is dramatic, while the overlap with Organic SERP remains consistently low.

GEO requires not only a platform-specific, but also a model-specific. I think it is wise to re-monitor the visibility across key prompt clusters as soon as a new model is being released.