EXHIBIT 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We consent to the incorporation by reference in Registration Statement Nos. 333-115700, 333-123962
and 333-132588 on Form S-8 of our reports dated March 16, 2007, relating to the consolidated
financial statements and financial statement schedule of Blue Nile, Inc. (which report expresses an
unqualified opinion and includes explanatory paragraphs relating to the adoption of Statement of
Financial Accounting Standards No. 123(R), Share-Based Payment, and the initial application of the
provisions of Staff Accounting Bulletin No. 108, Considering the Effects of Prior Year
Misstatements when Quantifying Misstatements in Current Year
Financial Statements) and report of
management on the effectiveness of internal control over financial reporting, appearing in this
Annual Report on Form 10-K of Blue Nile, Inc. for the year ended December 31, 2006.
/S/
Deloitte & Touche LLP
Seattle, Washington
March 16, 2007