In this analysis we will explore the amount of time it takes Buffer Publish users to upgrade to a paid subscriptions. We’ll look at all users that upgraded to a paid subscription in 2017 and 2018, and build some exploratory charts to get a feel of how long it takes these customers to upgrade.

In this analysis, we find the following facts:

- 33% of customers upgraded in 7 days or less (67% took more than 7 days)
- 44% of customers upgraded in 14 days or less (56% took more than 14 days)
- 55% of customers upgraded in 30 days or less (45% took more than 30 days)
- 79% of customers upgraded in 120 days or less (21% took more than 120 days)
- 83% of customers upgraded in 365 days or less (17% took more than 365 days)

```
select *
from dbt.user_upgrade_facts
where first_charge_at >= '2017-01-01'
and first_charge_at < '2019-01-01'
```

There are around 82 thousand customers that upgraded in 2017 and 2018.

## Number of Days to Upgrade

Let’s begin by plotting the distribution of the number of days it took these users to upgrade to their first paid subscription.

We can see that many users upgraded relatively quickly after signing up. However there is also a very long tail of users that took a long time to upgrade. To get a better understanding of the exact percentages, we can plot the cumulative distribution function (CDF).

This is how you interpret the plot: if you hover over any point on the curve (X), you will see a `y`

value that represents the proportion of users that upgraded in *X days or less*.

For example, if you find the point on the curve where number of days to upgrade = 7, you will see that y = 0.325. This means that 32.5% of customers upgraded for the first time within 7 days of signing up. From this, we can infer that 67.5% of customers took more than 7 days to upgrade. This method can be followed for any point on the curve.

- 33% of customers upgraded in 7 days or less (67% took more than 7 days)
- 44% of customers upgraded in 14 days or less (56% took more than 14 days)
- 55% of customers upgraded in 30 days or less (45% took more than 30 days)
- 79% of customers upgraded in 120 days or less (21% took more than 120 days)
- 83% of customers upgraded in 365 days or less (17% took more than 365 days)