In this definitive guide, experts from Ford, Google, eMarketer, AOL Latino and others provide insight on how to reach this growing, lucrative and often misunderstood market online.

Happy Cinco de Mayo! Do you know what it means? Has it become the "Hallmark Holiday" for marketing to U.S. Hispanics? Since today raises many questions and challenges about marketing to U.S. Hispanics, let's use it as a springboard for better understanding of this audience and the new online tools we can use to market to them.

While beverage companies in particular have defined the day as a "fiesta" with a vaguely Mexican or "Latin" flavor, most Mexicans do not even observe it in their country of origin. And many Americans misinterpret the holiday to be Mexican Independence Day, which is actually Sept. 16. More significantly, it means absolutely nothing to the 36 percent of U.S. Hispanics that aren't Mexican.

Without question, U.S. Hispanics have become very important among marketers not only because of their sheer size (44 million Hispanic consumers according to the 2006 U.S. Census data), but also because they will grow to 105 million by the year 2050. As this generally younger audience makes brand decisions, U.S. Hispanics represent an opportunity for many marketers to grow their business among a relatively underserved market, which is more open to product suggestions.

At the same time, marketing to U.S. Hispanics brings many challenges, including the multitude of countries of origin, levels of acculturation and usage of Spanish, English or both languages. In addition, Hispanic internet penetration is still quite low relative to the overall U.S. population (but much higher than in countries like Mexico). eMarketer says that 20 million Hispanics are online today, growing to 24 million in 2011.

The complexity of reaching this audience can intimidate many marketers as the potential for making mistakes is high. Fortunately, new online targeting technologies have ushered in a new chapter: marketers can now grow awareness and sales among U.S. Hispanics, overcome the challenges and create effective marketing campaigns that segment their target audiences correctly with measurable results.

In this article, I have brought together 10 experts from Ford, Google, eMarketer, AOL Latino and Terra, as well as leading authors and entrepreneurs who can help you avoid the mistakes in reaching this growing audience online and provide a roadmap of best practices. Following are their suggestions. Please comment or leave questions below, and be sure to check out the list of resources at the end of the article for more in-depth statistics and insights.