Area 51 proposals are automagically advertised on all sites. But some sites with Community Ads also choose to promote Area 51 proposals that are related to the topic of the site. (Still other people might use these banners to advertise proposals elsewhere.)
I've just seen the Latin Language proposal advertised on Academia.SE, showing the correct "51% committed". However, home-brew ads using the PNG file available on Area 51 show "90 followers", which judging by the "definition phase" graph was around January 2015.
Should be "51% committed", not "90 followers".
I asked this question 2.5 months ago on Area 51, but no answer is forthcoming, and as it affects advertising proposals in Community Ads across the whole network, I'm reposting it here.
Similarly, I've seen the "Korean Language" proposal ad, which showed "42% committed", however, the ad used as Community Ad on Japanese.SE shows "39% committed".
Update. Now, after 10 months with "90 followers", the file of the Latin Language proposal has been updated to show "54% committed", as it should. (Do the files update in accordance with how many people view them?) Maybe this was fixed, or just became an unreproducible bug =)