ProBargainHunter.com

Update 01/03: The promotion has had a limit of 2000 users which apparently was reached (see the comments to this post)

I have not spent the $100 I got from the previous promotion when it is time to get on a new one. :-) This is the best deal from Microsoft AdCenter I have seen so far.

Use promo code DM-2-1106 to open a new account before January 15, 2007 and get $200 in free ad clicks. The offer valid for new customers only (this usually means the email you use to sign-up should not already be in their database) and $5 initiation fee will apply.

$200 in free clicks from Microsoft AdCenter (via FatWallet)

If you fill in the form at this link there is a chance you will get $50 worth of clicks via Google AdWords network. The promotion is for new accounts only so be ready to shell out $5 sign up fee. The deal thanks to the eComXpo conference going on right now. More details available here.

Here is another promotion. This time it is a $50 from Microsoft (with a new account as well) to set up your advertising with MSN network. Forum discussion at DigitalPoint.

If you have not been already using either of the networks this might be a good opportunity to start. I am planning to do so with MSN.

Note. If you sign up on any of these deals make sure to read the fine print. I noticed that the MSN one requires you to use the credit within 90 days.