Absolutely a relevant question. I was going to put a few disclaimer paragraphs at the top but took them out at the eleventh hour because this post was already pretty long.
For the sorts of tactics in this post I'd say you definitely need product/market fit and a steady stream of incoming customers. Depending on the price of your products, the product mix and your target market this could be 50, 500 or 5000 customers/potential customers. It's more likely to be the upper two, in this case as you need a good sample size to get see any change and know that it's statistically relevant.
After I get through this series of post (or in the meantime, if I get a chance) I'll put together a post that addresses exactly what you've asked for: what 3-5 lifecycle emails should you ABSOLUTELY be sending from the word go and at what point should you implement new strategies like those mentioned here.
It'd be my pleasure :). chris AT getvero.com if you ever want to get in touch and chat directly too.