I think a lot of times people go into a launch with hopes that are really expectations. If expectations are too high it's natural to be disappointed when growth is a trickle. You want to compound users like you would an investment account.

I would service the piss out of every early user whether they explicitly ask for help or not. If you have something to serve those early people and they are happy they will tell others over time and will become the initial customer support contact for the referrals. Support demand won't necessarily be linear growth with user growth.

My preference is to bootstrap the core technology development as long as you can because you learn what you actually need as you go. Not what you think you need. Being very high hands-on with all early users will teach you how to build a passive customer service system or how to iterate your technology to fix common bottlenecks.

Once the core technology is in place and you've discovered a marketing niche that you can exploit at-scale, then, you consider taking money and investing it in user acquisition.

At the end of the day, it's all a speculation and you need to win some bets because you will lose plenty along the way. ;)