Hello and welcome! I'm pretty funny about giving out info like that -well, I'm downright adamant about it. I type transcripts and occasionally I've had to for tax purposes. What I did was call up the IRS and got an Employer Identification Number, or EIN. (You don't have to have employees to do this - you are the employee) Basically, it's a number you can give out for tax purposes, it's linked to your SSN, but only by the IRS. To me, it's sort of like using PayPal with vendors, and safer. You can get more info about it at the IRS web site.
That's a great idea Carrie. I also balked at giving them my SSN. I didn't need to when I was an affiliate at another place - especially when earning just a few dollars here and there (under $100). Not sure it is even reportable until you go over $2,000 (that's how it is with gambling winnings). So for someone that would generate lots of sales, I could see it. That's just not me. But that would be on our end, perhaps on their end they need to prove that money went out to someone.