Lumezanu et al. [18] perform a joint analysis of spam in email and social networks. Spam data from Yahoo’s web-based email service and Twitter are used to characterize the publishing behavior and effectiveness of spam advertised across both platforms. It is shown that email spammers that also advertise on Twitter tend to send more email spam than those advertising exclusively through email. Furthermore, sending spam on both email and Twitter has better exposure than spamming exclusively with email: spam domains appearing on both platforms are looked up by an order of magnitude more networks than domains using just one platform.