What the search engine does, for each user that uses esocsia and does about 45 searches 1 tree is planted,
Breakdown: https://blog.ecosia.org/tag/where-does-ecosia-plant-trees/

Ecosia has been around for 16 years, and its growing overtime.

The reasoning for the promotions, each search on other search engines like bing, or google goes to cooperate greed, where each of your search fills their pockets.
With using esosia each goes to planting trees.

Requirements: Full Member or higher

This may complete at any time, and/or price may lower at any time

To each user that does the following:

#1) https://www.ecosia.org/browser
Head over and download the brower or app

Screenshot proof imgur

#2) Attach your BTC Address