I have joined a number of sites and it is nigh impossible to visit all in one day but I try to visit them on alternate days. Some sites you, as a free member can only post every 3, 5 or 7 days. Here are a few: European Safelist, Viral Url, Lead Magnet, Traffic Adbar, Traffic Bonus, Traffic Adlinks, Mister Safelist, Postadsview, 10x Mailer, Adachiever, Email Myads, State Of The Art Mailer (SOTAM), Bweeble, Marketing Checkpoint, List Adventure, List Jumper, Lootclick, Clicksense, Listjoe, Unlimited Viral Ads, Reactive Ads, Easyhits4you, Guaranteed Solo, LOL Solo. Each of these sites I use to promote my online business to bring in associates and earn. I also promote the sites among each other, always offering some form of encouragement to join, which is the thing to do.