As someone who doesn't RP on this site at all, I'm probably not the person to ask.

But I do see people respond favorable enough to interest checks if the idea is interesting. It's a good way to make sure you have enough people to start an RP anyway. Success is always going to be up to the people involved however. 

I think an interest check is a good idea, but it's not a guarantee things will go smoothly. To avoid breaking any rules, I will not mention certain RPs that looked like they had a strong start, but faded due to OOC drama in the first few weeks of running.