• ViacomCBS's Paramount+ will have it investor presentation Wednesday, showcasing all of the content that will be on the rebranded CBS All Access service.
• The event will end a "moment in time" era of streaming presentations that have dominated media in the past two years.
• Disney's investor day showcased the power of its content, while Apple TV+'s investor day illustrated its lack of premium programming.

ViacomCBS will perform what's become a rite of passage Wednesday, trotting out executives to explain why its new streaming service is awesome and different from all others.

Wednesday's event will be the end of an era of sorts. Barring a surprise entrant from a non-media company, ViacomCBS's Paramount+ presentation will be the last of the major streaming investor days, which double as a consumer showcase of what's on each service.

There are a certain traits that make or break an investor day. Specifics on price, tentpole original shows, breadth of library content and hopefully a surprise or two.

Here's a look back at all of the major streaming launch events in the past 18 months ⁠— the good, the bad, and the ugly.

Apple TV+, March 2019

• Price: Unsaid (later turned out to be free for a year with the purchase of an Apple device, $4.99 a year thereafter). Apple has since extended the free trial by several months for its early subscribers.
• Subscriber forecast: Not given
• Tentpole original series: "The Morning Show"
• Prized library content: None
• Surprise: How bad the event was

Let's be honest, the Apple TV+ event was not good. This event happened in the way back, when people could see each other in person. Apple invited hundreds of its employees, reporters and a slew of celebrities (Oprah!) to explain its streaming vision in Steve Jobs Theater in Cupertino, Calif. But Jobs probably would not have been pleased. Apple had few shows, limited video trailers, zero library series or movies to showcase and the company didn't even reveal details about how much the service would cost. This was the first major streaming event, and it taught other companies what not to do.

Disney+, April 2019

• Price: $6.99/month, $69.99/year (free for some Verizon customers for a year)
• Subscriber forecast: 60 million to 90 million by 2024 (since updated to 230 million to 260 million)
• Tentpole original: "The Mandalorian"
• Prized library content: Pretty much ever Disney movie ever
• Surprise: The price

Disney shocked the world with its Disney+ price, and it put every other media company on notice. For less than $7 a month, Disney would give consumers access to practically every Disney movie, every Star Wars movie, the Marvel content catalog, The Simpsons, the best of National Geographic and new original shows like "The Mandalorian."

Nearly two years later, Disney's event continues to be the gold standard. Disney built on its introduction this past December with a slew of new content and an updated subscriber estimate that has blown away the field in "The Streaming Wars."

AT&T's HBO Max, October 2019

• Price: $14.99/month (free for some AT&T wireless customers). Some subscribers to HBO through their cable provider get HBO Max for free too.
• Subscriber forecast: 50 million U.S. subscribers, 75-90 million global subscribers by 2024
• Tentpole Original: None
• Prized library content: Everything HBO
• Surprise: Pricing HBO Max the same as HBO

AT&T pleased TV fans by pricing HBO Max ⁠— "where HBO meets so much more" ⁠— exactly the same as HBO. For HBO subscribers, that meant billions of dollars of new content for no extra charge. Unfortunately, even WarnerMedia executives felt AT&T botched the introduction of HBO Max by rushing it out before obtaining a tentpole original franchise. That's slowed conversions from HBO to HBO Max, as most of the service's best stuff has been the library of past HBO content. That's starting to change, though, as HBO Max rolls out new series, documentaries and the entire 2021 theatrical film slate at the same time each movie hits theaters.

Quibi, January 2020

• Price: $4.99/month with ads, $7.99/month without ads (free for some T-Mobile customers for at least a year)
• Subscriber forecast: Not given
• Tentpole Original: None
• Prized library content: None
• Surprise: Its existence

CEO Meg Whitman chose the Consumer Electronics Show to unveil Quibi, a service built for people to users to watch short 10-minute episodes or chapters of shows while waiting in line or killing time. Quibi said it planned to introduce more than 175 original shows and 8,500 short episodes in the 12 months following its April launch.

Yada, yada, yada, Quibi doesn't exist anymore. This service's failure wasn't a surprise. The speed of its collapse was.

Comcast's Peacock, January 2020

• Price: Free limited product with ads, $4.99/month premium with ads, $9.99/month without ads
• Subscriber forecast: 30 million to 35 million "active accounts" by 2024
• Tentpole Original: None
• Prized library content: "The Office"
• Surprise: A free version

NBCUniversal was originally going to charge about $10 per month for Peacock, but after Disney came in at $6.99, executives realized they had to change course. So Peacock's differentiator became its price: $0. Still, the free version only comes with some of Peacock's goodies, like just the first two seasons of The Office. And unless you count the "Saved by the Bell" revival as a tentpole original, I'm hard pressed to say Peacock has a must-see original series. Peacock's event was impressive. It was at NBCU's 30 Rock headquarters, in Studio 8H, where "Saturday Night Live" takes place. The Roots performed, and the sushi was delicious.

Discovery's Discovery+, December 2020

• Price: $4.99/month with ads, $6.99/month without ads (free for some Verizon customers for a year)
• Subscriber forecast: Not given
• Tentpole Original: None
• Prized library content: "90 Day Fiance"
• Surprise: Its positioning

Discovery CEO David Zaslav took a long time deciding if it made sense to launch a streaming service. He was ultimately convinced by others, including media executive Barry Diller, that his company could own the unscripted, non-fiction space. So Zaslav donned a Steve Jobs-style black turtleneck to make his pitch to investors and consumers in December, launching a companion product to what Starz CEO Jeff Hirsch refers to as "Tier A" services ⁠— Netflix, Amazon Prime Video and Disney+. Discovery announced last week it's on pace to have 12 million paying subscribers by the end of this month ⁠— a promising start.

Disclosure: Comcast owns NBCUniversal, the parent company of CNBC.