The normal version of the Bank of America Alaska Airlines Signature Visa comes with a 25,000 miles upon approval and a $75 annual fee. However, there is a new targeted link which offers the same mileage bonus and annual fee, but a $100 statement credit after spending $1000 within 3 months.
This link was discovered by a reader of One Mile At A Time and as explained there, you can apply for the offer when booking a ticket on the Alaska Airlines website at the ticket confirmation page.
The direct link above seems to take you to the offer without having to book a ticket through the Alaska website. However, use your own judgement when applying through that link. Also, if you do purchase a ticket through the Alaska website, you could indeed cancel that within 24 hours if you needed to.
I have updated this on the Alaska Airlines Visa Signature summary page.