We』re only able to accept credit or debit cards as a form of payment at this time for Akismet plans.
If you opt to purchase a Jetpack Security Daily, Jetpack Security Real-time, Jetpack Anti-spam, and Jetpack Complete plan which includes an Akismet Plus subscription, Jetpack does offer PayPal as a form of payment.
If you have more general questions about Akismet, please contact us here.