Smartphones’ capabilities are increasing every year—and so is the amount of time people spend on them. In fact, the average person in the U.S spends about four and a half hours on their phone each day. With so much screen time, it’s no surprise that marketers are so interested in optimizing their mobile marketing strategies to boost sales and gain new customers. But in their efforts to attract new customers, many marketers may actually be turning them away.

Whether it’s messaging customers too often after a purchase, overusing notifications or simply not adding enough value, these bad practices can turn new and even existing customers off your brand for good. For better customer retention and sales, avoid this list of ineffective practices and mistakes, courtesy of Forbes Communications Council, when building out an improved mobile marketing strategy.

Uncover more valuable takeaways from Stephanie Bunnell in Forbes.