Okay, I want to make a $19.53 purchase on pay pal and I saw the bill me later option, which says $10 back and no interest on my first purchase until April 2012.

Anyone have any experience with this? Is there a membership fee or something or if it's my first time/trail, I can do this with no strings attached?

Special Offer: Get $10 back, plus No Payments or Interest if paid in full by April 2012

Complete your purchase before midnight ET on September 30, 2011 to receive this limited time offer. This offer is non-transferrable.

$10 back on your first purchase

You'll receive $10 back as a statement credit for your first Bill Me Later purchase through PayPal.
Valid for first-time Bill Me Later customers only. If you already have a Bill Me Later account, you are not eligible to receive this offer.
Limit 1 per customer. Please allow 1-2 billing cycles for this amount to be reflected on your Bill Me Later statement.

No Payments + No Interest if paid in full by April 2012

Interest will be charged to your account from the purchase date if the purchase balance is not paid in full within 6 months.
Select "Yes, I'd like No Payments/ Interest if paid in full by April 2012..." to be eligible to receive the promotional offer for each purchase.
You'll receive monthly statements...
Pay in full by the promotion expiration date as listed below and you will not be charged interest.
If you do not pay in full by the promotion expiration date, interest will apply from the date of purchase at an Annual Percentage Rate of 19.99%.

For example if purchase is made in: Date to pay in full by to avoid interest (Promotion Expiration Date)
September 2011 April 1, 2012

If approved, WebBank will extend credit to you for the amount financed to pay for your purchase. WebBank will pay the merchant on your behalf to pay for the purchase.
Edit:
Yea, I'm reading now on google that they check your credit score/doc you points on your score from their frequent check ups.

I have no credit as it is. Not worth 10 dollars.

Deciding against this.