I think IEO is popular and its in much demand by investors nowadays because of the profits it offers. However be mindful that not all projects in IEO is going to succeed.
Yes there is great demand for IEO in the market especially the IEOs that are conducted on Binance because of great and profitable reasons. I have plans to go for the next IEO to be conducted on Binance and have already a wallet over the exchange. In addition, you could also invest in IEO on other good exchange if you think they are worth putting in your money.
I have not seen any IEO have listed on any exchange. Are you confused about this information because the Binance project often chose to make IEO very strict