What are some alternatives?
When comparing Coinbase and Kraken, you can also consider the following products
Binance - Cryptocurrencies exchange platform
Bitfinex - Bitfinex is the largest and most advanced crypto-currencies trading platform.
LocalBitcoins.com - LocalBitcoins.com is a person-to-person bitcoin trading site.
Uphold - Move, convert, transact and hold any form of money or commodity. Instantly, securely and for free.
Electrum - Electrum is an easy to use Bitcoin client.
Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.