1) Broadly 2) Commonly 3) Far and wide 4) Generally 5) In a widespread way 6) Usually 1) Considerably 
• (adv.) To a great extent; widely; largely; as, a story is extensively circulated.
Ex·ten'sive·ly adverb To a great extent; widely; largely; as, a story is extensively circulated. 
[adv] - in a widespread way 2. [adv] - to a great extent
extensive, extensively, extensiveness 1. Having great extent; covering a large area; vast. 2. Having a wide scope, power, effect, influence, etc.; far-reaching; comprehensive.
adverb in a widespread way; `oxidation ponds are extensively used for sewage treatment in the Midwest`