Martin|Williams Advertising promoted Zach Pentel to senior social media strategist.

Arnold Worldwide promoted Neela Pal, executive vice president, global director of brand and business strategy, and Tom Guerin, executive vice president, executive director, to managing partners at the agency.

R/GA hired Chris Apostle as managing director, client services. Apostle joins R/GA from Razorfish, where he led the agency's CPG practice.

Mash Media Solutions hired Stephen Tapp as chief executive officer.

PromaxBDA hired Shawn Anderson as director of marketing and communications.

Meeri Park Cunniff has been named senior vice president of programming strategy for MTV. Cunniff most recently served as senior vice president of programming and on-air for TeenNick where she oversaw day-to-day operations.

LBi hired Pete Johnson and Mike Hartman as group creative directors. In addition, Debby Chow was named director of CRM and Erin Keefe was named strategy director, health. Lastly, Christopher Enright was named chief innovation officer and Taylor Noguera as US director of business development.

Tania Salter joined Wing as vice president of production. Salter joins the agency from Grey Hong Kong, where she was executive producer, P&G for Asia One.

G2 hired Brian Hull as executive creative director in G2 USA's interactive marketing practice. Hull most recently served as group creative director at Organic.

PJA Advertising + Marketing named Robert Davis senior vice president, digital marketing for its east and west coast operations.