Verizon, AT&T, Sprint and T-Mobile detail holiday marketing strategies

The fourth quarter holiday shopping season is the most critical sales period for the nation's top wireless carriers. The fourth quarter is typically when they spend the most on advertising, and it's usually when they add the most subscribers.

According to historical data from research firm Nielsen, Verizon Wireless (NYSE:VZ) and AT&T Mobility (NYSE:T) have consistently spent more on marketing in the fourth quarter than Sprint (NYSE:S) and T-Mobile US (NYSE:TMUS), which makes sense, given the disparities between the sizes of the companies' subscriber bases and revenues. In the fourth quarter of 2012, Verizon spent $476 million on marketing, according to Nielsen (though that figure includes money for Verizon's wireline operations as well). AT&T Mobility spent $364.3 million, Sprint spent $222.2 million and T-Mobile spent $234.7 million.

Looking at this year's holiday season, the carriers will have plenty of reasons to increase their marketing spend. According to research firm comScore, for example, "Cyber Monday" after Thanksgiving is expected to be the heaviest online spending day in history, growing 20 percent year-over-year to around $2 billion.

But what exactly will each of the nation's Tier 1 carriers focus on in their holiday advertising campaigns? FierceWireless spoke with marketing executives from each of the top carriers to find out.

Here is a breakdown of what to expect from the Tier 1 carriers through the end of the year:

Verizon, AT&T, Sprint and T-Mobile detail holiday marketing strategies