What I do is click on the "news" tab. Then I click a title of one of the articles. Then I leave it a minute or so (I don't open them in a new window, and I don't click on anything within the article itself). If I get nothing (as usually happens) I click on the title of another news article and wait another minute or so. I usually do this a few times before giving up. I'll come back in an hour or a few hours and try a few more articles. I average about 2 ZDaily wins a day (3ZB each most of the time).
EDIT: Forgot to say, when you get a "win" a picture of a ZB bill pops up with a captcha to complete before you get credit.