Wrong. facebook use push, as google-chat, ICQ, yahoo-msn, Microsoft MSN, and ANY OTHER Instant Messaging (IM) System. It is a must for INSTANT messaging. Whatsapp uses jabber protocol modified to avoid security. Facebook uses plain jabber. So they use similar battery power. Google-talk uses a modified jabber for reducing net use and then improving battery life. Microsoft MSN uses more battery. Don't know about Yahoo MSN. Skype is wich more battery use.