Some great answers here, let me add my views here. My experience on this topic relates to seeing a mobile app grow into millions of users, a content site growing to millions of uniques and ecommerce site growing over 500k in a few months.

Before getting into actions. Let's consider what scaling means first. Scaling is the simple of action of taking something you're doing well (or that fits well to a set of customers), and multiplying it in size considerably.

That means that if you don't do something well to start with, and you start to multiply it, the result is a grand mess and a shit ton of lost money.

Having established that we need something that works well for a set of customers, how do we know when that's true?

Well there's several ways of going about this:

1. Ask them and let them tell you. Probably not a good idea. Nobody likes to be mean.
2. Check their behaviour and see if it matches their intent. Best way to go.

Depending on your product you can choose different metrics to gauge if you have fit or not. It depends on the type of business you want to scale.

Ideally, as scaling means spending a bunch of money into acquiring new users, what you want is an approximate understanding of the return you will get for your investment.

For this reason, revenue is always a great metric to watch. Even better, lifetime value.

In terms of behavior though, it's really all about retention here. If your users come back fanatically and can't seem not to live without your product on a regular basis, then you have high chance of fit. Look at your cohorts and how they behave. Look at time spent on product.

You can also survey them to support this data.

Once you get numbers that stick. There's your green light to scale.

Good luck with your project. If you'd ever need more information on how to execute all of the above, then simply give me a call and I'll help like with many other companies.

The best way is to go to growthhackers.com. It's where most of us growth hackers spend our time during non-working hours :) Here in clarity I'm not sure how many of us are working on growth hacking, but I personally run a CRO and growth agency. Anytime you need to chat, simply let me know.

Great question. The simple answer is yes. Now a more complex answer. This is what I've learnt after successfully optimizing for large e-commerce companies and SaaS:

CRO is not only a matter of testing opportunities, but a matter of timing and resources. Especially within organizations where both are limited.

When you have many testing opportunities, the ideal thing is to focus on the ones that are closer to the money exchange between customer and you. That means getting the sales funnel backwards, and working through the motions.

Why? You focus first on the people that are about to give you their money, but couldn't for any sort of reasons. They're the lowest hanging fruit.

The other side of the coin is, a massive influx of new leads can also bring great benefits. Even if new people fall of the funnel, a great deal will still go through. Only issue is, if you're paying for that traffic, then you're losing a lot of money.

So start closest to the money. Make sure that part of the funnel is fixed. Then either move to middle of the funnel or don't be afraid to open the top funnel too to get that landslide of new users.

If you need more advice, simply give me a call.

Best regards
Javier