Selling digital marketing services to 27 million small businesses (SMBs) could become a $2 billion new business by 2016  for newspaper companies, according to Ken Doctor.

Some benchmarks:

• ReachLocal, with $430 million in most recent 12-month revenue.

• Hearst’s LocalEdge, a reincarnation of its Buffalo yellow pages business, with 1,000+ full-time salespeople.  Customers include the Minneapolis Star Tribune (Radius, averaging client paying $426 per month), and the Dallas Morning News (508 Digital), Morris Communications, Wehco Media, Newsday, and the New York Daily New

• Dallas Morning News Speakeasy, a 12-person start-up, with an average client paying $3,600 per month.

• Buffalo News and Pittsburgh Post-Gazette, using Guarantee Digital.

• Tribune 435, focusing on $10,000+ per month clients.

• Vocalize Mobile, an early-stage company now in 60 markets.

Ken Doctor’s well-researched piece is here.

With ad revenue dropping by more than half in 5 years, to $22 billion, the $2 billion could make up barely 6 months of average industry ad revenue declines.