> Linear growth can be worse than no growth

Not sure I get this one right. For me, some growth is better than nothing. If your growth is linear, it means that you have something like n new users every week, which is probably because they found it through ads or something, but they don't recommend it to their friends - otherwise, you would have every week n+knumber_of_users[previous week]* and the growth would be exponential. I suppose that's why OP is saying this, but I think the real metric is not growth, but retention. Better to have a few users who stick with your product.

Is that what the OP means?