Somebody’s got some esplainin’ to do. Keynote Systems said that in the week leading up to the Obama campaign’s highly anticipated text announcement, things weren’t working too smoothly. In fact, based on its tests, Keynote believes between 40% and 50% of people who subscribed to get the VP selection text message may not have received the message in a timely fashion or “very likely” never received the text at all.

Keynote conducted 600 tests on the Obama ’08 Campaign short code from Aug. 13 to Aug. 22. Results revealed it achieved consistent availability only slightly more than 50% of the time. And this time, it doesn’t look like you can blame the carriers’ networks, said Shlomi Gian, director of mobile business development for Keynote.

Tests were conducted in San Francisco and San Diego across major carrier networks, and the chances of a network outage in both cities at the same time are pretty unlikely, he said.

SinglePoint, the aggregator working with apps provider Distributive Networks for the Obama campaign, referred questions about the text message campaign to Obama’s campaign headquarters, which did not respond to a request for comment.

Gian said he suspects that while the aggregator may be capable of handling a high volume of text messages for a voting campaign like “American Idol” over the course of a short time, the longer Obama campaign, where people signed up over the course of a couple weeks to get the message, might have been an issue. “It’s almost like comparing a sprinter to a marathoner,” he said. Nielsen Mobile estimates that 2.9 million U.S. mobile subscribers received a text message from the Obama campaign over the course of Friday, Saturday and Sunday.

One recommendation Keynote often gives to content providers or brands doing SMS campaigns is to have relationships with more than one aggregator as a back-up.

A number of technical variables could have impacted the undelivered text messages, according a source not involved in the Obama VP message. Alykhan Govani, CEO of aggregator MX Telecom North America, said: “In any messaging campaign, and especially one on the scale of Obama’s, a number of variables can impact message delivery. These include carrier downtime, application downtime and system capacity.” MX Telecom places an emphasis on backup and redundancy to combat that and works toward the 100% reliability that clients expect, he added.

Meanwhile, VeriSign this week reported it saw another record-breaking quarter for mobile messaging. VeriSign’s combined mobile messaging networks enabled more than 52 billion messages in the second quarter, up more than 20% from the previous quarter.

Particularly as more brands explore using short codes on a mass scale, Gian said a solution – which Keynote offers – for testing and monitoring common short codes is needed to ensure the delivery of critical information and reliability.