The seeds sown among thorns are people who hear the message, but then life's worries and the temptation of money choke the message so that they become fruitless.
The seeds that fall among thorns are those who hear the message but it's choked out by life's distractions—worries, wealth, pleasure—so they don't produce anything.
Some seeds fell on good earth and after they grew they produced a harvest one hundred times more than what had been sown.” After he told them this, he called out, “If you have ears, then listen!”