Musical festivals have an understandable appeal to advertisers, as they draw a generally younger and affluent audience. According to research from Eventbrite, the average festival-goer is 32 years old and earns more than $75,000 per year. With the unofficial festival season kicking off this month at the Coachella Valley Music and Arts Festival in Indio, California, marketers are taking steps to get in front of attendees.

Coachella draws hundreds of thousands of attendees over its two weekends, April 12-14 and April 19-21—in 2017, more than 250,000 people attended, according to Time. In the four weeks heading up to the show this year, the price of billboards on I-10 leading to Coachella Valley, the site of the festival, increased by 31 percent. The billboards now run $8,000 to $20,000 and out-of-home ad buying-and-selling platform AdQuick expects them to be seen by hundreds of thousands of people. Much of the content running on the billboards ahead of the festival is designed to target the large population of Millennial attendees. AdQuick notes music agents and the companies behind various apps have shown particular interest.

Billboards aren’t the only way brands are trying to connect with festival attendees. Several companies, ranging from McDonalds to American Express, are hosting events in the area surrounding Coachella. These offer unique promotional products, stylish backgrounds and “selfie” opportunities for the music festival staple—Instagram posts. As the event draws near, companies of this scale also hire celebrities, who are largely in attendance, to further advertise their products.