Exhibit 4.13

[eCollege Letterhead]

August 15,
2003

Oakleigh
Thorne
Blumenstein/Thorne Information Partners I, L.P.
PO Box 871
Lake Forest, IL 60045

Re: eCollege.com Registration Agreement

Dear
Mr. Thorne:

Reference
is made to that certain Stock Purchase Agreements dated as of August 13, 2003 (the "Stock Purchase Agreements"), among eCollege.com, a Delaware corporation (the
"Company"), and the investors listed therein (the "New Investors"), pursuant to which the Company has agreed to sell, and the New Investors have agreed to buy approximately, 2,900,000 shares of the
Company's common stock, par value $0.01 per share (the "Common Stock"). Under the terms of the Stock Purchase Agreements, the Company has also agreed to register the Common Stock sold to the New
Investors under the Securities Act of 1933, as amended (the "Securities Act"), by filing a Form S-3 Registration Statement (the "Form S-3") with the Securities
and Exchange Commission.

The
Company respectfully requests that Blumenstein/Thorne Information Partners I, L.P. (the "Investor"), in exchange for the extension of the term of the Registration Agreement (as
defined below) as described below, hereby: (i) waives its piggyback registration rights granted under Section 2.A. of that certain Registration Agreement dated September, 2000 (the
"Registration Agreement"),
between the Company and the Investor, with respect to the filing of the Form S-3 and any amendments thereto; and (ii) waives the Company's obligation to comply with
Section 8.A. of the Registration Agreement to the extent that the registration rights granted under the Stock Purchase Agreements violate Section 8.A. of the Registration Agreement.

In
exchange for the Investor's waiver of the matters referenced above, the Company hereby agrees to amend the Registration Agreement to extend the term thereof until September 1,
2005. The amendment to the Registration Agreement shall be effective upon the Investor's acceptance of this Letter Agreement. Except as shall be explicitly amended by Investor's acceptance of this
Letter Agreement, all of the terms and conditions of the Registration Agreement shall remain in full force and effect.

To
acknowledge the Investor's waiver of the matters referenced above, please sign both of the copies provided, retaining one copy for the Investor's files and returning the other
executed copy to the Company.

This
Letter Agreement shall be governed by, and construed in accordance with, the internal laws of the State of New York, without giving effect to the principles of conflicts of law.

This
Letter Agreement may be executed in one or more counterparts, all of which shall be considered one and the same agreement and shall become effective when one or more counterparts
have been signed by each of the parties and delivered to the other party, it being understood that both parties need not sign the same counterpart.



|Sincerely,                                                |                                                                 
|--------------------------------------------------------- | ----------------------------------------------------------------
|ECOLLEGE.COM                                              |                                                                 
|By:                                                       | /s/DOUG KELSALL EVPDoug Kelsall, Executive Vice President       
|ACCEPTED and AGREED TO this 15th
day of August, 2003, by: |                                                                 
|BLUMENSTEIN/THORNE INFORMATION
PARTNERS I, L.P.           |                                                                 
|By:                                                       | Blumenstein/Thorne Information Partners, LLC,
as General Partner

|By: | /s/OAKLEIGH THORNE |                
|--- | ------------------ | ---------------
|    | Name:              | Oakleigh Thorne
|    | Title:             | Co-President   

[Signature page to Letter Agreement]



QuickLinks