Apple wowed fans with iOS 7 at this year’s Worldwide Developers Conference, and since the new mobile OS has been available for download, the number of iPhone and iPad devices running the beta software for iOS 7 has nearly doubled vs. iDevices running iOS 6 during the same time period last year, a new study shows.

Onswipe, a mobile optimizing start-up based in New York City, found that 0.28 percent of all iPad visits to its mobile sites were running iOS 7 by July 1, and 0.77 percent of all iPhone visits to its sites were running iOS 7 by June 17. While these adoption numbers seem small, they’re remarkably higher than the adoption numbers of iOS 6 from the same time last year. By June 25, 2012, 0.19 percent of all iPad visits were running the early versions of iOS 6, while only 0.38 percent of all iPhones were running iOS 6 beta software. Onswipe CEO Jason Baptiste, in a statement to TechCrunch, said developers “are around twice as excited” about iOS 7 than they were with last year’s iOS 6.

But what’s causing this rise in adoption for the iOS 7 beta? Here are four reasons why users are willing to give iOS 7 beta a try before its public release date this fall.

1. iOS 7 Is Simply Better Than iOS 6

iOS 6 was a mixed bag since Apple’s much-maligned Maps app marred the overall experience for many users, while iOS 7 is a feature-ridden build with many important new functions like Control Center and AirDrop, plus a top-to-bottom redesign of the operating system. In other words, there is much more to be excited about with the release of iOS 7 compared to iOS 6, which was somewhat lackluster in the broad scheme of iOS releases.

2. Apple’s Low Barriers Of Entry

Developers are clearly excited about iOS 7 – Apple sold out tickets for WWDC 2013 in record time this year (under two minutes) – but Baptiste posits that more everyday users are adopting the beta for iOS 7, even buying into the $99-per-year Apple Developer Program just to get their hands on the pre-release version of iOS 7 before its release date this fall. To some, $99 may not seem like much of a barrier if that means getting iOS 7 before everyone else. So even though Apple advises users against using beta software – even the iOS 7 beta is unstable not fully ready for major use – considering the low barriers to entry for iOS 7, plus the unprecedented level of hype surrounding the platform’s release, these contributing factors likely played a key role in the increased usage of iOS 7. (For directions on how to download and install iOS 7 beta to your iPhone, iPad or iPod Touch, check out our step-by-step guide.)

3. The Role Of The Media

Hype plays an important role in most Apple products, so considering the outlandish level of writing, reporting and blogging about iOS 7, the redesign and the new features in iOS 7 may have been too much for some users. The release date for iOS 7 is expected to be in mid-September, a full 100 days after the unveiling of iOS 7; to some, 100 days with iOS 7 means 100 days they won’t have to wait and obsess about an operating-system experience they can enjoy right now.

4. The Growth Of iOS

Apple reserves its beta software releases specifically so iOS and Mac developers have plenty of time to ready their own software and optimize everything before the public-ready software reaches the public. With regard to iOS, which is Apple’s most popular platform by far, the mobile ecosystem of iPhone, iPad and iPod is growing every day and is expected to grow substantially with the release of two new iPhone models this year, as well as a handful of other product launches including new iPads, and even a brand-new iOS device, the iWatch. With iOS 7 set to power all of these next-gen devices, adopting iOS 7 early and preparing one’s software for the major public release in September is strategic from a business and monetary standpoint, considering how many developers will be rushing to optimize their products for iOS 7 after it’s already in the wild. Developers understand that iOS 7 will likely be the most important software release Apple has ever distributed, and they want to adequately prepare themselves and their products for consumption as soon as iOS 7 goes live.

Apple iOS 7 Release: What’s Inside?

For those unfamiliar, iOS 7 features a complete revamp of the font, style, colors, icons and textures of iOS to make it a familiar but entirely new experience, as well as a massive feature-ridden iOS build to boot. Most notable among the new iOS 7 features: the useful Control Center that contains quick access to important settings; the built-in parallax that shifts the background image in response to one’s movements; a new way to multitask apps; the AirDrop feature for sharing photos or documents with other iPhone users in the area; and much more. We expect Apple has already set the iOS 7 release date for Wednesday, Sept. 18 -- exactly 100 days after the unveiling of iOS 7 -- which would also precede the release of at least one new iPhone model on Friday, Sept. 20.

Check out our visual guide on iOS 7 to learn more about the design of iOS 7, some of the surprise features we discovered in the first iOS 7 beta, our collection of 80-plus screenshots of iOS 7, and of course, should you want to download iOS 7 before its release date this fall, check out our step-by-step guide on downloading and installing the iOS 7 beta to your iPhone, iPad and iPod Touch.

What do you think of iOS 7? Let us know in the comments section below.

Follow Dave Smith on Twitter