I want to talk a bit about the ability of creating mulitple accounts with the main pay per click networks: google & yahoo.

Both Yahoo & Adwords, allow multiple account creations.

These are also, how the people serve multiple ads on the same keywords!

Multiple Accounts on ADWORDS (Google Adwords)

Yes, You can have unlimited adwords accounts. 10,000 accounts if you really wanted too. I think.

To create multiple accounts on adwords, they have a tool called MMC or My Client Center. This special account for adwords is used for large advertisers who use more than one account. These can be, Third-Party Agencies, Search Engine Marketers (SEMs), Search Engine Optimizers (SEOs), and automated bid managers (ABMs). MCC is an umbrella account for multiple adwords accounts.

To Sign Up for a MCC account, signing up to join the Google Advertising Professionals program.

*Remember that once you sign up for My Client Center, your personal AdWords account will be moved over to this new master account.

Multiple Accounts on YSM (Yahoo Search Marketing)

Yes, You can have unlimited ysm accounts. You can also have thousands of accounts under the same credit card number.

Here’s a quote from Minterest.com

X. Yahoo’s guidelines don’t allow you to open multiple accounts using the same Yahoo! Search Marketing promotional link/code/coupon.  Once they locate the account(s) that were opened with the same promotional link/code/coupon and same contact/billing information those accounts will be taken offline for promotional code abuse.

But if you were to create a brand new account which is not associated to any other account you have, then Yes, you may use a different promo code to create a separate account.

In order to open another account and apply another promotion code, you have to sign up for a new account with a new user name and a separate email address.

And Yes, You can use the same Credit Card on as many accounts as you want to create. Thus, there is no limit to the number of accounts an advertiser can fund with a single Credit Card or PayPal account (You can now pay your Yahoo! Search Marketing bill via PayPal), subject to availability of funds in the card.

Yahoo! Search Marketing Customer Solutions team says in an email: “You are more than welcome to open any amount of additional accounts using the same credit card, with any promotional offer that you may have being honored.”

Here is another email from Yahoo! Search Marketing Support Team: “You are able to open separate accounts using a promotional credit if you sign up with the link that offers the Promo Code. If we were to find out that the multiple accounts were created to advertise the same site in each account, the accounts will be taken offline for promotional code abuse. There can only be one promotional code per account and it must be a separate domain and site in each account.”