CainIV - 7:03 am on Nov 16, 2010 (gmt 0)

Effective is relative to your business model and objectives. Will it gain you short term rankings? I would suggest it will.

Will it gain you long term links that will drive rankings for years? No, at least not for highly competitive genres.

Will it increase the number of backlinks that could potentially be looked at by a manually reviewer down the road and favor against you in their judgment of your website? Possibly.