An article on The Next Web explains that the HTC Sense storage service is going offline on April 30 for a renovation, which could explain the HTC storage partnership with Dropbox, which is now integrated into the HTC Sense software. In any case, users of other mobile devices wanted to take advantage of the free storage offered to HTC One phone owners and quickly found a workaround.
An online forum discussion on the XDA-Developers site explained how to get the free Dropbox storage on non-HTC One phones. The Dropbox Basic account only provides 2GB of free storage, so the extra 23GB was tempting and forum users chimed in after nabbing the free space with the workaround.
Dropbox responded on its own forum:
The method to earn 23GB that is being circulated on the XDA Developers forum and on other blogs and forums is illegitimate. We plan to remove any space received using this method."
In fact, some people who used the workaround reported that their extra storage had indeed disappeared.
Meanwhile, Dropbox recently doubled the amount of free space users can get by inviting friends to Dropbox:
For every friend you invite that installs Dropbox, you’ll both get 500 MB of free space. If you’ve got a free account, you can invite up to 32 people for a whopping total of 16 GB of extra space. Pro accounts now earn 1 GB per referral, for a total of 32 GB of extra space."
Dropbox is also back-starting credit to users who already referred friends to the service. Referring friends might not get you 23GB of free space, but it won't install malware on your systems, either.