Reaching out to young adults online is a great tool, but Jessica Coblentz urges ministry to connect online with offline:
Online social media is an appealing tool for young adult outreach. Young adults already use it. It is often free. It can be tempting to spend time and effort reaching out to young adults online that would be better spent on in-person ministry and relationships with them. Assess on a regular basis whether your online ministry is an effective means to offline ministry. If your Facebook page has 400 fans but the same three people keep showing up for your events consider another approach.
You’ll find more principles for outreach to young adults in the Essentials section.