---
title: Google Adwords algorithm
date: "2005-09-24T12:00:00Z"
categories:
  - links
wp_id: 545
description: I found an experiment comparing two identical sites on AdWords. A new account’s traffic collapsed after dropping its bid from $1.00 to $0.40, while an established account thrived at $0.10, suggesting the algorithm favors seniority or penalizes rate decreases.
keywords: [google adwords, adwords algorithm, click-through rate, ppc bidding, search engine marketing, algorithmic bias]
---

Interesting experiment to test the [impact of changing the rate for Google Adwords](http://www.pbs.org/cringely/pulpit/pulpit20050922.html). Two identical sites have Adwords account. One has an established account paying $0.10 per word. Another is a new account, and begins by paying $1.00, then lowers it to $0.40. The former got 15,000 click-throughs regularly. The latter started just above 15,000 and fell to 1,200 after the rate drop. Does the Adwords algorithm favours rate increases disproportionately (and hence is evil?) Or is the fact that the former site an established one create the difference?