> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mention-me.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Understanding Retention and Reactivation Periods
> Understand how Mention Me retains and purges customer data, and how reactivation lets long-inactive customers be referred again.
Mention Me holds customer data for a defined period and then purges it automatically. Alongside this, a separate setting called reactivation controls whether a customer who hasn't purchased in a long time can be referred again. This article explains both concepts, the default periods we apply, and how you can request changes.
## Retention Periods
Retention periods determine how long we keep a customer's personally identifiable information (PII) before it is purged. Purging doesn't delete the underlying event record. It overwrites the PII with random data, prefixed with "Purged", so the event trace remains for auditing while the personal data is removed.
We apply four default retention periods, each covering a different type of customer:
| Customer Type | Default Retention Period | Description |
| ------------------------------ | ------------------------ | ----------------------------------------------------------------------------------------------------------------- |
| Referees who haven't purchased | 2 years | Customers who were referred but haven't gone on to make a purchase |
| Uninterested referrers | Forever | Referrers who saw an offer but never engaged with it any further |
| Referrers who don't share | 4 years | Referrers who engaged with an offer but have never shared it with a friend |
| Other non-referral customers | 2 years | Other customers Mention Me may know about, for instance those who've engaged in an NPS survey but not in referral |
Customers who successfully complete a referral, either as a referrer who shares or a referee who is referred, are **not** purged automatically. We keep these records for the lifetime of the contract to track incremental referrals, support customer service, prevent gaming, and deliver personalisation. All customer records are purged once a client churns, typically within a month of the contract ending.
### Why These Periods Were Chosen
The 2-year and 4-year defaults are based on aggregated sharing and purchasing behaviour across our client base:
* Referral is a comparatively slow channel: only 59% of shares happen within the first 3 months of enrolment, rising to 89% by 24 months and 96% by 36 months. It takes 48 months to reach 98%. This is why the default retention period for referrers who don't share is 4 years.
* Similarly, it takes around 2 years for 98% of referees who've been given an incentive to make their first purchase, which is why the default retention period for referees is 2 years.
This data is aggregated across all clients and isn't specific to any one industry, so individual results may vary.
Shortening these retention periods can reduce referral volume. One client that set their referrer retention period to just 2 months found that referrers were being purged before they had a chance to share, which measurably hurt their programme's performance.
### Requesting a Change
You can override the default retention periods if needed. If you're an existing client, speak to your Client Success Manager. If you're a prospective client, speak to a member of our pre-sales team, and we'll configure this during onboarding.
This retention data can also be a useful reference if you're compiling your own Data Protection Impact Assessment (DPIA).
## Reactivation
Without reactivation, a customer who hasn't purchased in a long time can never be referred again by friends or family, even though they're technically still an existing customer. This means any potential for that customer to re-engage through a referral is lost.
Reactivation solves this by treating a long-inactive customer as if they were new. Once a customer hasn't purchased within the reactivation period, their friends can refer them again, giving the brand a way to re-engage dormant customers and potentially win back a lapsed relationship.
For example, a customer who made several purchases around five years ago but hasn't transacted since would, without reactivation, be permanently excluded from being referred again. With reactivation enabled, that customer becomes eligible to be referred once more after the reactivation period has passed.
### Default Reactivation Period
By default, reactivation is set to 12 months: a customer becomes eligible to be referred again once 12 months have passed since their last purchase.
You can adjust this period to suit your business, in whole months from 1 to 240 (for example 12, 18, or 36 months). Setting the value to 0 disables reactivation entirely.
### Requesting a Change
To change your reactivation period, contact our support team with your preferred number of months, or let us know if you'd like reactivation disabled.