Is Twitter a Good Channel for Slump Marketing?

Can Twitter be an effective marketing channel? This Marketing Sherpa article/case study shows how JetBlue and Carnival Cruise Lines have been successfully using Twitter.

“Slump Marketing” - Thank you Marketing Sherpa for the title

Recessions have traditionally not been a friend of marketing — but I believe that savvy online marketers will discover that Internet marketing provides ample opportunities to prosper and profit during any slump or recession that weren’t readily available in the last slump/recession.