Third party widgets, ads, and analytics are gaining in popularity. This query shows the most popular scripts across all websites:
SELECT count(*) as num, ROUND(AVG(respBodySize/1024)) as avgKB, url FROM [httparchive:runs.2014_11_15_requests] WHERE resp_content_type contains "script" GROUP EACH BY url ORDER BY num desc LIMIT 100
Here are the top 10 scripts for Nov 15 2014:
Here are the top 10 scripts for Aug 15 2014:
The top four scripts were the same over this three month period. The use of Google Analytics has held the same (~187K). Facebooks rs.src usage has dropped from 47K to 37K. (Digging deeper this is largely due to version fragmentation and overall usage is about the same.) Twitter dropped from 36K to 34K. Plusone dropped from 36K to 33K. The other scripts indicate a growth in Google ads.