what does 30% a quarter mean?

And business data decays a lot faster than consumer data: 30% a quarter in some sectors. That means your entire list dies every year.

What dose "30% a quarter" means here?

• I understand this as meaning: Business data decays 30% faster than consumer data in some sectors when compared every 3 months. Dec 21, 2014 at 16:54
• @Joe I understand it to mean that business data decays by 30%, and that consumer data decays by something less than 30%. Dec 21, 2014 at 21:14
• It's worth noting, the second sentence is simply incorrect. If you lose 30% a quarter, you lose about 76% per year, not 120% as they seem to imply. Dec 22, 2014 at 0:45
• The data grows stale at a steady rate, with up to 30% of the original data volume becoming stale per quarter. Typically, this applies to things like sales leads, hardware inventory, etc, things which have a high volume of churn. To state that the data decays at 30% of the remaining volume (like radioactive material) suggests that a contact list you buy one year might still have viable contacts 5 years later (a volume of 1,000,000 still has about 800 useful contacts), when in reality, you will have had no viable contacts for about 80% of that time. Dec 22, 2014 at 2:05

It means 30% per quarter, or 30% each quarter, where a quarter is three months (a quarter of a year), a common period in accounting.

By the end of the first quarter, 30% of the data available at the beginning of the quarter becomes obsolete. You have 70% of your consumer data still "fresh" and applicable.

By the end of the second quarter, 30% of the remaining 70% becomes obsolete too. And so on.

• No, it's 30% of the original volume, not the remaining volume. Data grows stale at a fairly constant rate. Compare: 1 year later, all data is useless, versus your description, where some small amount of the data would always be useful, even 20 years later. Dec 22, 2014 at 1:44
• Tnank you for the comment, @phyrfox! You could be right, but I'm not sure. CorsiKa's comment concurs with my post. You could post your own answer, explaining why you think we should abstract the annual declines from a constant "start-of-the period" figure, and if it turns out right, I will scrap mine. Dec 22, 2014 at 2:55
• @phyrfox - yes, the sentence says "the entire list dies every year", but it couches the mode of the list's expiry in ambiguous terms, at least to me. I'm not much versed in English texts related to financial maths. Dec 22, 2014 at 3:00
• It probably won't make a difference, because my answer is unfortunately long-winded, but it does describe (generally) how businesses tend to make purchasing decisions and therefore why lists have a limited shelf life. Dec 22, 2014 at 18:07
• Thank you for the posted answer, @phyrfox! I'll read it later. Dec 22, 2014 at 18:15

Without the entire quote, this question is out of context. I found the original text, quoted here:

1. Is my house list jammed with dead souls?

It doesn't matter how great your creative is. If you're not cleaning house regularly, the dead names on your list will be pulling down your response rate.

Over half of marketers check customer data is accurate sometimes or never.

And business data decays a lot faster than consumer data: 30% a quarter in some sectors. That means your entire list dies every year.

This author clearly has a weak grasp on the English language (e.g. "great your creative is"), or has poor grammar checking software, but the idea they are trying to convey is well known for educated/experienced business professionals. While I'm not educated in business, I am experienced in so-called "enterprise solutions," especially CRM (Customer Relationship Management) systems, which really has been an enlightening experience.

Most businesses run with four distinct quarters, usually aligned with the calendar, but with some variations as to the exact start and end dates for each quarter, usually for tax purposes. Budgets are based on these fiscal years. In other words, most businesses allocate a certain amount of money to spend in a quarter, and once that money is gone, it means that they risk missing performance metrics (net operating costs, etc). Since this money is allocated before the quarter starts, or possibly even before the fiscal year starts, that usually pushes purchasing decisions out between one (3 months) and four quarters (12 months).

This means that most businesses have a very small window of time to try and work their leads (potential customers) and groom their current client base, often just a few months. After all, the client wants to buy product between a particular 3 month window so it can be reported during that time against profits, taxes, etc. If a business misses this window, some other business will have made the sale by that time.

Some companies are in the business of collecting and selling data (this is where your lists may come from). Once you have a fresh list, that data starts decaying at an approximately steady rate. This occurs because of a variety of reasons: a person changes positions in a company, leaves a company, the company chooses a different direction, finds an alternative (possibly less expensive) solution to the problem that led them to appearing on the list, etc. Note that some industry sectors decay slower than others, because their purchasing decisions go out even further, 18 months or more in some cases.

Regardless of the reason, this rate of decay is exceptionally predictable within major industry sectors, and this will become apparent with experience selling and buying in these sectors. According to this author, over 50% of marketers don't bother to keep fresh data, and so are wasting resources, such as sending emails, cold calls, etc, that will never produce sales.