Google Analytics (GA) is a free service offered by Google that generates detailed statistics about the visitors to a website.
It's main highlight is that the product is aimed at marketers as opposed to webmasters and technologists from which the industry of web analytics originally grew. It is the most widely used website statistics service, currently in use at around 57% of the 10,000 most popular websites.
Twitter is a social networking and microblogging service, owned and operated by Twitter Inc., that enables its users to send and read other user messages called tweets. Tweets are text-based posts of up to 140 characters displayed on the author's profile page. Tweets are publicly visible by default, however senders can restrict message delivery to their friends list. Users may subscribe to other author tweets—this is known as following and subscribers are known as followers.
