If you know what is an IPO, then it makes this easy.
But instead:
is unregulated
performed using crypto currency
can be achieved with smaller budget, and with just an idea.
i agree with you, IPO will do much help to understand ICO, and i think one more difference is that everyone can participate in ICO easily while IPO only open to institution
I also found that starting off with the concept of IPO's works good. With the main difference that investors don't buy a percentage of a company but rather a share of a (future) network. If the network becomes valuable and gains traction, a return can be made on this share. Depending on wether the network / platform already exists during the ICO, it's either a security or utility that you are essentially buying from a legal perspective.