PayPal is only optional if you're a moron.
I thought I had found a deal to buy a lot of four James Bond 007 rpg books of the eBay. The lot included the core book, the indispensible Q Manual, the For Your Information GMs supplement and an adventure. Certainly a sufficient amount of Bondery to kickstart a campaign. The min bid was $9.99 and the s&h was 8, not a great deal, but still less than 5 bucks a book.

But this dorkus won't accept PayPal. Game over, man. I use alternative payment methods when I really want a rare item bad, but 007 stuff comes up all the frickin' time. No PayPal is a deal breaker. When it comes to online shopping of any kind, I just can't make an impulse purchase without the PayPal. The extra steps involved in getting a money order or calling and giving some schmuck a card number just kills my consumer buzz.