As smartphone users adjust to a new world of metered data plans, they are taking notice of their data usage and just how much bandwidth is consumed in the background by their apps.

There is a new class of “bad apps” that consume dramatic amounts of background bandwidth through constant network signaling for updates. One of the worst offenders is email. Email is still the most used app on a smartphone and not many vendors (besides SEVEN) have optimized their apps.

A case in point is a trial that one of our U.S. carrier customers ran with five of its subscribers switching them from the K9 mail app to SEVEN:

• Customer 1: Previous Month 1.1 GB; Current Month .62 GB (43% decrease)
• Customer 2: Previous Month 1.8 GB; Current Month .7 GB (61% decrease)
• Customer 3: Previous Month .08 GB; Current Month .01 GB (87.5% decrease)
• Customer 4: Previous Month 4.4 GB; Current Month 1.3 GB (70% decrease)
• Customer 5: Previous Month .14GB; Current Month .048 GB (65% decrease)

Although there were a couple of fewer days in the current month, the results are still dramatic, especially for the big email users like customer four.

Separately, we’ve confirmed this ability to make a big impact on email bandwidth in other tests we’ve done with our Open Channel traffic optimization platform, where we were able to reduce data consumption from the Yahoo! Email app for Android by almost 75%.

While email is bad, it is by no means the worst (Angry Birds with mobile advertising can be a huge offender!), and the popularity of apps means that the average smartphone can have many of these data suckers quietly adding to their bandwidth consumption over the course of a month.

Carriers will start to feel the pain of this as customers become dissatisfied with data usage reporting and what they consider to be unfair overage charges. Adding SEVEN email and Open Channel can fix this problem and free up bandwidth for future growth.