How to measure the amount of days between first and second conversion
I do not know if it is possible, therefore this question. Is it within Google Analytics possible to measure the number of days in between the first and second conversion? And perhaps also between the second and third conversion?
If you see for example that people make a new purchase 1 to 2 months after their first purchase, you can customize your AdWords ads. using custom audiences. This way you can get extra visibility during that period. Like to know if this is possible.
Re: How to measure the amount of days between first and second conversion
There is no standard report exactly match what you asked for in GA. There are a few alternative reports you may want to check out: (1) Conversions> Ecommerce > Time to Purchase > Days to Transaction ; (2) Multi-Channel Funnels > Time Lag. But again they're not exactly what you want.
It's actually hard to make such report standardized in GA. The business scenario you described works the best when you have a large amount of subscribers with recurring purchase needs, like diapers, and they must be sticky and organically return to your site. Because the results of this kind of report will be heavily influenced by your marketing campaigns - how often you reach out to returning users. And eventually you want to take actions like remarketing to them periodically. So it must not be a self-proven loop. Think about your business first.
Now let's talk about technical stuff, how to do this in custom reports.
One way is to set a custom dimension and post the "days between transactions" value to the dimension once the second transaction happen. The value is calculated in your back end, and of course the user must have an account and login.
Seems like I just did a short blog post