Shown here, are a series of posts from anons who have been monitoring the sales figures each month for the respective comic releases. The numbers show a steady downward trend for sales, but the biggest drop comes from the 2014 My Little Pony Annual, written by Ted Anderson. The numbers, which we verified through 3rd party sites such as Comichron confirm a total sales number of 15,292 copies.
For comparison's sake, that puts it as the lowest-selling individual new pony comic release for the month, trailing Friends Forever 9 by over 1500 (nearly 9% drop) and even further behind the main series #23 by nearly 4200 copies, a difference of over 20% in sales.
For a proper comparison, last year's 2013 annual sold 18,614 copies, showing a same-series drop of nearly 18%. The first issues of IDW's My Little Pony were each clearing 40,000 copies.
The factors for this noticeable slide could be numerous, though many people believe it to be in response to the controversy associated with the 2014 annual, and the actions of Ted Anderson. More data will be required, but it is uncertain how much farther the IDW sales will slip over time.