The solar eclipse is causing a flurry of excitement, and businesses want to cash in. Here are some of the best promotions and tie-ins.

• Millions of tourists have gathered along a strip of North America to witness the solar eclipse. 
• The wave of eclipse tourism is expected to boost economies and local Artisans, restaurants, and businesses have been preparing.
• This is how the communities lucky enough to lie in its path are tapping into eclipse fervor. 

Millions of people are gathering across North America to watch the total solar eclipse on Monday.

The best views of the eclipse can be found along a route that stretches across 13 states, known as the "path of totality." Its where AirBnbs have been booked up, and the biggest festivities are planned.

Up to 3.7 million people are expected to travel to the area — which cuts a diagonal line across the US from Texas to Maine — to see the eclipse, joining the 31 million who already live along its trajectory.

Altogether, the phenomenon could deliver a $1.6 billion boost to local economies, according to the Texas-based economic consultancy Perryman Group.

From eclipse-themed festivals to special deals and commemorative souvenirs, this is how local communities and businesses have been gearing up to welcome eclipse tourists and cash in on Monday's rare celestial phenomenon.

The essential viewing accessory — protective glasses — aptly placed on sale next to Pink Floyd's "Dark Side of the Moon" album at the Rock & Roll Hall of Fame in Cleveland over the weekend.

Souvenir buttons for sale at the Carbondale Eclipse festival in Illinois.

'Total Eclipse' merchandise advertized outside of the Charlie's store on in Llano, Texas.

T-shirts on sale in Makanda, Illinois, which is at the crossroads of the 2017 and 2024 eclipses, experiencing full totality for both.

More limited edition t-shirts on sale in Carbondale, Illinois.

Alternatively, get your eclipse "guardian angels" in Russellville, Arkansas.

In honor of the eclipse, this Country Fair mini-mart in Erie, Pennslyvania is offering customers any breakfast muffin or croissant for $1.99 throughout April.

A billboard promotes the breakfast sandwich offer - named the "Black Out Special."

A local coffee store posts an eclipse-themed menu in Perryville, Missouri featuring a "cosmic latte"

Dawn MacDonald, the owner of Crowe's Tattoos in Maine draws an eclipse tattoo on the neck of a customer.

MacDonald told a reporter that she has had a steady stream of customers wanting one of her special eclipse designs.

An antique shop gets 'Totality Prepared' ahead of the solar eclipse in Waxahachie, Texas.

Soaps for sale in Waxahachie, Texas have been named with the eclipse in mind. "Hachie Eclipse of the Heart," "Luna," and "Mother Earth" are pictured here.

Larger brands are also cashing in on the space theme. Krispy Kreme has released a Solar Eclipse Donut, which is available until the end of Monday.

Fast-food chain Sonic has created a limited edition "Blackout Slush Float."

Community festivals and viewing events will provide an added boost to local economies. A digital billboard promotes the day on a busy road in Addison, Texas.

A sign in the town square greets visitors in Paris, Texas.

The town of Houlton in Maine is hosting a 4-day event featuring entertainment, education, and markets to celebrate the eclipse.

People dressed as alien creatures walk through the main square during the eclipse festival in Houlton.

A fireworks show was held in the main square on Sunday.

A cardboard cutout of Jesus featuring solar eclipse viewing glasses at the Carbondale Spring Fest in Illinois.

Hundreds of schools in Canada and the US are closing or letting pupils go early so that they can enjoy the eclipse.

Some businesses, like grocery store Wegmans, have taken their employees into consideration as well. Wegmans are giving staff 30 minutes off "to enjoy this once-in-a-lifetime event."

Employees at this Illinois pizzeria aren't so lucky — it will remain open during the eclipse.