I just want to add that LoMoStar also has a really good value proposition to the companies that want to promote themselves on it (and I'm not just talking about IPOs).
Part of it is that the envelope cover image can be an ad, and they pretty much have a guarantee that people will see it.
Next, users of LoMoStar tend to remember the users that post good envelopes, and they will look for their avatar when deciding what envelope to open. If that avatar is a company logo, with the company name as the username, this builds a lot of goodwill towards that company.
All the company has to do is make sure the envelopes they post are actually good. And the cost of a good envelope on LoMoStar is much lower than usual advertising costs.
And finally, there is the messaging feature. When you open someone's envelope, you "follow" them, and can't unfollow for 48 hours. During this time, the envelope owner can message you. They can also have a group chat where they can provide additional envelopes to encourage people to read the chat. That kind of direct access to potential customers can be a very valuable thing for a company.
The only concerns I have are related to how LoMoStar will be able to handle increased growth. If it becomes popular, there will be a lot more crappy envelope spam that will need to be filtered. There will also be a lot of automated bots trying to game the system. Once the geolocation feature goes live, they will also face the issue of GPS spoofing, which is very difficult to fight against.
How LoMoStar handles those concerns will be what makes it or breaks it. It's still too early to tell, but I honestly hope they can come through.
All great points, thanks @cryptoscopia