A Glowing Spiral Galaxy Live Wallpaper with thousands of glowing stars


  •  3D Spiral Galaxy
  • Real 3D glow
  • Multiple coloured galaxy themes
  • High performance OpenGL 2.0 rendering
  • Lots of options to fully personalise your galaxy
  • Jelly Bean 4.2 Daydream support

Cosmic Glow Live Wallpaper

Cosmic Glow Live Wallpaper (Free)



After reading about others’ success with Reddit self-serve advertising, we decided to try it ourselves,  advertising Gyrospace 3D (our most successful app) for 2 days on the /r/android subreddit.

Self Service

The reddit advertising model is explained fully here but the key points are that you bid a daily amount against others and get allocated a proportional share of the traffic over a 24 hour period. Your reddit submission/link will sit right at the top of the page. Bids are secret and not disclosed to anyone else, so you can’t be sure how much traffic you will be allocated.

The minimum bid is $20/day for site-wide adverts and $30/day for subreddit specific adverts. We decided to just target the /r/android subreddit, which would mean a larger share of a smaller, more relevant pie (245,000 readers currently).

The app we were advertising was well received when first posted as a regular submission in November last year, receiving 223 upvotes and 87 comments.

The Results

The Advert

Reddit Stats

The Numbers

Almost 50k impressions and 900 clicks for $60, giving cost per 1k impressions (CPM): $1.22 and cost per click (CPC): $0.067

Fewer impressions than the average of other adverts run over the same period ( $0.22 CPM and $0.14 CPC site-average), but a higher click-rate offset that to reduce the CPC.


The CPM and CPC are going to be highly dependent on how many people bid against you; casually browsing the subreddit over that weekend I don’t recall seeing any competing adverts, so I doubt anyone else bid for the subreddit specific slot.

Our CPM was 5.45 times the average, but our CPC was much better, at half the average cost meaning that our advert had a higher click rate compared to the site wide average – 1.81%, where the average is only 1.57%

Edit: I miscalculated the CPC, it wasn’t near as bad as first thought.

Why the poor results? It could be that most readers have already seen the app, that the chosen graphic or title wasn’t interesting enough, or it could be that subreddit exclusive ads give a lower CPM than site wide ads. Another possible factor could be that /r/android readers browse on their mobile devices; reddit reader apps generally don’t display sponsored links, although I doubt that would have a significant impact, especially during the weekend.

It’s fairly safe to assume that the most significant factor is that the subreddit just isn’t large enough for subreddit specific ads to be worthwhile.

Our Android app doesn’t run any analytic software, so it’s impossible to tell how many people purchased the app as a direct result of the sponsored link, but compared to the following weekend, the app had almost exactly the same amount of daily installs – no significant boost in purchases. The free version of the app showed slightly higher daily downloads while the ad was live, but again nothing significant.

$0.07/click seems very good as online ads go, requiring 1 sale for every 15 clicks to break even.

It would be interesting to run the campaign again, site wide and compare the numbers, including some analytic tracking would also provide invaluable information but so far we’ve followed the path of least permissions – i.e. no internet permission.

The following are known issues:

White screen on Asus Transformer Infinity (cause is known, solution is not simple). Temporarily disabled purchases for this device. Fixed
• Image/gyro Drift on some devices. Fixed 1.0.5
Black bars on some devices/images Fixed 1.0.3
• Settings screen is always portrait