What is Paypal Fee in Adengage payment ?

I earned $21.3 on February. Today I get my payment. But They prior take $0.42 as Paypal Fee. What is this Paypal fee ? In in Payment history in paypal, I receive $20.88 with no fee. Please explain what is this? Is this Cheating ? :confused:

Payments:
PayPal xxxxx@gmail.com [xxxxxxxxxxxxxxxxxxxxxx] 20.88

PayPal Fees Paypal fees 0.42

Balance $0.00
My paypal Transaction details below:

Transaction Details
Payment Received (Unique Transaction ID #xxxxxxxxxxxxx)
Business Name:
AdEngage, Inc.
Buyer Email:
paypal@adengage.com
Payment Sent to:
xxxxxxxxx@gmail.com
Business Contact Information
Customer Service URL: http://www.adengage.com
Customer Service Email: contact@adengage.com
Customer Service Phone: 310-640-0101
Amount received:
$20.88 USD
Fee:
$0.00 USD
Total:
$20.88 USD
Date:
13-Mar-2009
Time:
15:45:57 PDT
Status:
Completed
Subject: […]

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