The most difficult thing is to attract fist 100k users. what advantages do you have to attract your first 100k users?
Promotion is very important thing to atract first 100k users. How do you plan to promote the project? what money will you use for promotion? will be your own funds or it will be money collected during IEO?
If you conduct IEO, then it should be a popular exchange with a large trading volume, but usually you have to pay a lot for IEO ... Therefore, I think that it is necessary to attract traders with some unusual conditions!