Yep, those pesky themes that users didn't want -
http://franklion.co.uk/GEN-LINKS/SNAG-0113.png
That is a pic of the figures for one of mine in 2007, 6 months after it came out. (an AMO bug means you add on the download figures of the top Incomplete - No Files version)
That weekly download figure was a bit of a one-off high spot, but, yeah, top themes in those days were getting 100,000 - 300,000 downloads a week.
Extension writers didn't like it much (quite a few devs were also extension writers) as their figures were far lower and we were getting all the glory. Then came Personas, which people just weren't buying into and themes were still burying them.
Mozilla's solution? - they froze the all the counter figures for 2 months in late 2007 and when they came back, the extension download figures were as expected like before and the theme figures were 10% of what they were across the board.
At AMO, they even tried to deny/dispute the previous theme figures, until we showed them the screenshots (they had forgotten that arty types who make themes always do screenshots, instead of geeky copy 'n paste) They had no answers, but just did a 'because I say so' on us. This was the guy btw
Cameron Nicks of Shift fame packed it in and I left AMO in 2008. Since then, I've been told, there have been a few more less drastic 'downward adjustments' on theme figures and, of course, the continual hiding of where they are and devs bad mouthing Complete Themes ever since.
For what? Just so that their Personas could take off because users had no other option? Instead of creating or competing on a level playing field, they chose to deliberately destroy one of their main competitive edges over other browsers. As the skill level in producing Personas is near zero, then pretty obviously, Chrome and all the other browsers immediately also brought out their versions of it.
N.B. My old pals at Mozilla have all now left and this new bunch are already pretty well aware of what I think of them, which does give me a certain freedom to express myself freely here.