Though I’ve posted on this topic recently, I’ve had requests for a more specific look at how to start and maintain data today for future analytics endeavors. So, some tactical and specific advice:
1a) Observations: Your stats guys will always want more observations because it allows them more precision in their results.
1b) Change: At some point the world is different enough that any results based on that world will be irrelevant. How fast your world is changing in your corner of the world is up to you, but 3 years is a reasonable minimum.
1c) Of course, Cost: Though storage costs are falling extraordinarily quickly, there are still costs in setup time, systems work, perhaps consultants, etc.
2a) Geography: Obviously keep it only at the level in which it’s relevant to your business: if you’re an online-only retailer with no regional pricing or advertising differences, there’s no need to keep geo data based upon IP.
2b) Product: Rarely a bad idea to keep as granular as available, and even invest the time in mapping data to the products. For marketing or advertising sources, involve your agency.
2c) Channel: If you have more than one channel, segment, or set of customers, keep the data mapped to those levels. Don’t be afraid, by the way, of using codes like “All” or “None” if it makes sense.
2d) Time: Unless you’re doing very detailed online tactic optimization, no need to keep anything deeper than daily, and in most cases weekly is just fine.
3a) No need to keep it:
i) An out-of-home billboard in Tucson: Not likely, unless you’re going to make billboards a larger part of the portfolio
ii) The iPhone app with 2,000 downloads: Not likely large enough (unless it’s direct response and is driving significant sales)
3b) Yes, keep it:
i) The 3-day inventory clearance event we held at the end of last season: Yes- price moves the needle.
ii) Website layout or navigation changes, or even changes to the IVR system at a call center: Yes, these drive surprisingly large changes
iii) Anything done by an agency: Yes- you’re spending on it, keep it, as relationships (and agency contracts) change over time
Hope this helps. And when in doubt, don’t hesitate to contact your analytics partner.