Reaching consumers with commercial messages grows ever more difficult, but some Boston-area agencies are testing a surprising tactic: simplicity.

Some of the most memorable advertising produced by local ad gurus in 2012 avoided the convoluted outreach that has become so common when campaigns stretch from TV and print to social media and mobile devices. Whether the ad was trying to explain the choice for health care or a new gadget, the best commercials stuck to a basic tenet and didn’t wander far from it.