If you are a social media man­ag­er or a com­mu­ni­ty man­ag­er, you need to know a secret: a new iOS social app is enchant­i­ng a vast – and con­stant­ly expand­ing – army of users and has just caught the atten­tion of some seri­ous investors.

Whis­per a secret

Meet Whis­per, the app that lets you anony­mous­ly share secrets with oth­ers in the form of charm­ing, post­card-style pho­tos with text over­laid. Co-founders Michael Hey­ward and Brad Brooks real­ized that social net­works linked to users’ real iden­ti­ties had a prob­lem. When peo­ple are con­cerned about their image, as they are on iden­ti­ty-based social net­works, they tend to post only pos­i­tives about them­selves. Accord­ing to Hey­ward, this leads them to over­es­ti­mate the hap­pi­ness of oth­ers and to under­es­ti­mate the extent of the prob­lems they share.

He explains: “We saw a huge white space of things that peo­ple were not pub­lish­ing, and want­ed to give peo­ple a place to share these things that they wouldn’t feel com­fort­able putting out on social networks.”

A social media manager’s dream discovery

This is the kind of hid­den-in-plain-sight white space that the job­bing social media man­ag­er or com­mu­ni­ty man­ag­er will rec­og­nize as pure gold, to mix metaphors a little.

Whis­per resem­bles sites such Post­Se­cret in spir­it; how­ev­er, it offers a lot more, which is per­haps why it has just raised $3 mil­lion in a Series A fund­ing round led by Light­speed Ven­ture Part­ners. It offers real-time, mobile post­ing that lets peo­ple com­mu­ni­cate ‘live’ in a way that Post­Se­cret nev­er has. Whis­per has extra tools to let peo­ple reply to posts imme­di­ate­ly and, for those will­ing to pay for it, it fea­tures a pri­vate mes­sag­ing option.

Putting pri­vate mes­sag­ing behind a pay­wall has proved a can­ny move, push­ing rev­enue upwards and improv­ing the qual­i­ty of what gets shared. Hey­wood and Brooks didn’t want the plat­form del­uged with solic­i­ta­tions or attempts to use it as a per­son­al mar­ket­place. When you pay, you post more judiciously.

Whis­per’s pop­u­lar­i­ty amongst col­lege stu­dents is boom­ing and it is also being used by mil­i­tary per­son­nel, some of whom are on active duty in the Mid­dle East. Since its launch in Novem­ber, the num­ber of users has dou­bled every month; in March the app notched up one bil­lion page views and 800,000 pri­vate messages.

With an Android ver­sion in the pipeline, prospects look seri­ous­ly good.