Remove duplicate xlsx, simplify card wording

Lets-Encrypt.xlsx

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:0083644b13a811a368c4f7c68205019201f9845e138fdccab59f949efc2f5213
-size 451692

README.md

@@ -25,56 +25,46 @@ size_categories:
 
 ## Overview
 
-This dataset analyzes Let's Encrypt adoption across the world's top 5,000 companies.
+This dataset lists 5,050 large companies whose websites were found to use SSL/TLS certificates issued by Let's Encrypt. Each row carries firmographic context for the company: industry, employee band, country, locality, founding year and LinkedIn profile.
 
-It identifies companies whose websites use Let's Encrypt issued SSL/TLS certificates, providing a snapshot of Let's Encrypt adoption among large organizations.
+It is intended for technology research, cybersecurity analysis, technographic research, competitive intelligence, market analysis and data science.
 
-The dataset is intended for technology research, cybersecurity analysis, technographic research, competitive intelligence, market analysis, and data science.
-
-Source and full statistics: **[Let's Encrypt usage statistics on StackScan](https://www.stackscan.com/technology/lets-encrypt)** — global heatmap, usage by country and industry, top websites and companies, and the full list.
+Full Let's Encrypt statistics, including the global heatmap, usage by country and by industry, and the top websites, are published at [StackScan](https://www.stackscan.com/technology/lets-encrypt).
 
 ## Dataset Highlights
 
-* 5,050 large companies, one row per company, no duplicate domains
-* Every company in the file is a Let's Encrypt adopter — adoption is the selection criterion, not a column
+* 5,050 companies, one row each, with no repeated domains
+* Every company in the file uses Let's Encrypt, so there is no adoption column. Adoption is the selection criterion
 * Every company has 5,001 or more employees
-* Firmographic context included: industry, headcount band, country, locality, founding year, LinkedIn profile
-* Suitable for research, visualization, segmentation, and machine learning projects
+* 142 industries and 140 countries represented
 
 ## What is Let's Encrypt?
 
 Let's Encrypt is a free, automated, and open Certificate Authority that provides SSL/TLS certificates. It enables websites to deploy HTTPS without purchasing certificates from traditional commercial certificate authorities.
 
-## Files
-
-| File | Rows | Notes |
-| ---- | ---- | ----- |
-| `Lets-Encrypt.csv` | 5,050 | Same content as the spreadsheet; this is the file the dataset viewer reads |
-| `Lets-Encrypt.xlsx` | 5,050 | Excel copy for manual analysis |
-
 ## Dataset Fields
 
-15 columns. Coverage is the share of the 5,050 rows where the field is populated.
+The data is in `Lets-Encrypt.csv`: 5,050 rows, 15 columns. Coverage is the share of rows where the field is populated.
 
 | Column | Type | Coverage | Description |
 | ------ | ---- | -------- | ----------- |
-| `Popularity Rank` | int64 | 100% | Website popularity rank; lower is more popular. Ranges from 5 to 1,959,064 |
+| `Popularity Rank` | int64 | 100% | Website popularity rank, lower being more popular. Ranges from 5 to 1,959,064 |
 | `Domain` | string | 100% | Primary website domain. Unique across the file |
 | `Company Name` | string | 100% | Company or organization name, lowercased |
-| `Company Size` | string | 100% | Employee band. Two values only: `5001-10000` (2,245) and `10001+` (2,805) |
+| `Company Size` | string | 100% | Employee band. Two values: `5001-10000` (2,245 rows) and `10001+` (2,805 rows) |
 | `Year Founded` | float64 | 73.4% | Founding year |
 | `Industry` | string | 99.7% | Industry label, lowercased. 142 distinct values |
 | `LinkedIn URL` | string | 100% | Company LinkedIn profile path |
 | `Locality` | string | 85.1% | City or region, where available |
 | `Country` | string | 100% | Company or website country. 140 distinct values |
 | `TLD` | string | 100% | Top-level domain. 355 distinct values |
-| `Language` | string | 0.6% | Detected site language. Largely empty |
-| `Instagram` | string | 0.4% | Instagram handle. Largely empty |
-| `Twitter` | string | 0.2% | Twitter handle. Largely empty |
-| `YouTube` | string | 0.2% | YouTube channel. Largely empty |
-| `TikTok` | string | 0.1% | TikTok handle. Largely empty |
+| `Language` | string | 0.6% | Detected site language |
+| `Instagram` | string | 0.4% | Instagram handle |
+| `Twitter` | string | 0.2% | Twitter handle |
+| `YouTube` | string | 0.2% | YouTube channel |
+| `TikTok` | string | 0.1% | TikTok handle |
 
-The five social and language columns are present for schema compatibility with other StackScan exports and are populated for fewer than 1% of rows. Treat them as optional.
+The language and social columns are populated for fewer than 1% of rows.
 
 ## Methodology
 
@@ -102,17 +92,17 @@ This dataset can be used for:
 * Website infrastructure can change over time.
 * Results represent observations from the dataset's collection period.
 * The dataset should not be interpreted as an official statement from any company regarding its technology stack.
-* Because every row is an adopter, this file supports questions of the form "what do Let's Encrypt adopters look like?" It cannot on its own answer "what share of large companies use Let's Encrypt?", which needs a comparable non-adopter sample.
+* Every row is an adopter, so the file describes what Let's Encrypt adopters look like. Measuring what share of large companies use Let's Encrypt would require a comparable sample of non-adopters, which is not included here.
 
 ## Citation
 
-If you use this dataset, please cite it and link back to the source page.
+If you use this dataset, please credit StackScan and link to the source page.
 
-**Plain text**
+Plain text:
 
 StackScan. (2026). *Let's Encrypt Adoption Among the Top 5,000 Companies* [Data set]. StackScan. https://www.stackscan.com/technology/lets-encrypt
 
-**BibTeX**
+BibTeX:
 
 ```bibtex
 @misc{stackscan_lets_encrypt_2026,
@@ -125,7 +115,7 @@ StackScan. (2026). *Let's Encrypt Adoption Among the Top 5,000 Companies* [Data
 }
 ```
 
-Source page: [Let's Encrypt usage statistics](https://www.stackscan.com/technology/lets-encrypt) — global heatmap, usage by country and industry, top websites and companies, and the full list.
+Source page: [Let's Encrypt usage statistics](https://www.stackscan.com/technology/lets-encrypt).
 
 ## License
 
@@ -135,4 +125,4 @@ Attribution must name StackScan and link to the source page:
 
 > Data from [StackScan](https://www.stackscan.com/technology/lets-encrypt), licensed under CC BY 4.0.
 
-For academic or published work, use the [citation](#citation) above instead.
+For academic or published work, use the citation above.