Financial Scams via Craigslist

“A Craigslist user allegedly swindled a West Des Moines man out of $2,600 last week, according to a West Des Moines police report.
A West Des Moines woman told police on Friday that she received an email in late June from a man responding to her Craigslist ad. The woman placed the ad because she was looking for secretarial work, the report stated…
She told police her first task was to receive a check in the mail, deposit the check, wait 24 hours before withdrawing the money, and then transfer that money to someone in Mississippi”

Are these types of scams common?

Yes, and very profitable, apparently. That one is a textbook example.

The most common.

Common as muck.