What are some alternatives?
eBay - Buy and sell electronics, cars, fashion apparel, collectibles, sporting goods, digital cameras, baby items, coupons, and everything else on eBay, the world's online marketplace
Facebook Messenger - Facebook Messenger is a faster way to message.
Amazon - Online shopping from the earth's biggest selection of books, magazines, music, DVDs, videos, electronics, computers, software, apparel & accessories, shoes, jewelry, tools & hardware, housewares, furniture, sporting goods, beauty & much more
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Openbazaar - A free online marketplace to buy and sell goods / services using Bitcoin. OpenBazaar is a peer-to-peer ecommerce platform with no fees or restrictions.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.