About this tool


The tool uses statistical properties and benchmark ROI estimates to workout the minimum spend required for econometrics to accurately measure marketing effectiveness.

Spend Selector was designed and built by magic numbers.

Please do let us know how it’s helped and if there are any improvements you can think of.


Information and data published by Gracious Economics Ltd t/a magic numbers (Magic Numbers) on the Spend Selector tool (spendselector.magicnumbers.co.uk) (the Website) is supplied by Magic Numbers. With respect to output of the Spend Selector tool, you acknowledge that there are uncertainties inherent to the data and you take full responsibility for making your own evaluation of the accuracy of such data and shall have no claim against Magic Numbers with respect to such data. Magic Numbers does not guarantee and cannot be held liable for the information made available on the Website and may change the information at any time without notice. You must not rely on the information on the Website and you acknowledge that you must take appropriate steps to verify this information before acting on it.

MAGIC NUMBERS PUBLISHES THE WEBSITE “AS IS” WITHOUT ANY WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, AS TO THE OPERATION OF THE WEBSITE, THE ACCURACY OF THE INFORMATION OR DATA ON THE WEBSITE (IN SO FAR AS SUCH WARRANTIES MAY BE EXCLUDED UNDER ANY RELEVANT LAW) AND TO THE EXTENT PERMITTED BY LAW, MAGIC NUMBERS SHALL NOT BE LIABLE FOR ANY LOSSES OR DAMAGE WHETHER DIRECT OR INDIRECT (INCLUDING, WITHOUT LIMITATION DIRECT OR INDIRECT LOSS OF PROFITS), CONSEQUENTIAL, SPECIAL OR OTHERWISE INCIDENTAL THAT MAY RESULT FROM USE OF THE WEBSITE HOWSOEVER ARISING.