I like Mainstreet as a diversification strategy, to get some exposure to businesses not directly related to crypto. What's interesting is that it provides access to the private equity market, which is an illiquid market not normally accessible to small investors such as myself. But by "securitizing the blockchain", Mainstreet is essentially creating a way to make that market liquid and open to everyone who meets their KYC standards.

It seems many people are having trouble getting past the validation on their sales page. It's a bit buggy (I suspect they didn't test it very well). They are recommending that anyone having trouble send them an e-mail with the required info that the web site asks for, and then they'll straighten things out.