Many Web developers these days feel a sleep-depriving mix of unbridled enthusiasm and nagging concern over Facebook's social-network platform.

Opened to external developers three months ago, the Facebook platform and tools are well-designed and offer developers generous revenue opportunities rare among social networks, along with a fast-growing and deeply engaged community of people.

However, this paradise is already getting soiled by developers who, eager to spur the adoption of their applications, design them with self-promotion features that many say are deceitful and trigger annoying and abusive actions, like bulk unsolicited e-mails and intrusive message displays.

Although Facebook has acknowledged the problems and in recent weeks outlined corrective measures, it's critical for the company to quickly tighten its rules and unleash stricter penalties, developers say.

"It's definitely a problem that needs to be solved. There are additional steps Facebook could and should take," said Ali Partovi, CEO of iLike, which rebuilt its music-discovery site within Facebook in May.

Looking for holes

As things stand now, the situation is a cat-and-mouse game, with developers seeking and exploiting loopholes in its terms of service and the company plugging them after the fact, he said.

By then, however, the damage is done, and the developer who exploited the loophole boosted adoption of his application, to the detriment of competitors who respect the terms' spirit, Partovi said.

That prompts honest developers to look for the next loophole as a defensive competitive measure. "That creates an unnecessarily bad environment," he said. "If the rules were simply enforced with more clear penalties, these companies would all fall into line quickly."

Partovi said his company has been watching this situation from the sidelines, because, in its category, iLike has a dominant position and feels little competitive pressure.

But he sympathizes with developers embroiled in competition with each other. "When you see your direct competitor exploiting a loophole and growing very rapidly and beating you, it's hard to resist the temptation," he said. "To some extent the blame is on Facebook."

Building business in Facebook

This comes from someone who otherwise couldn't be happier with the Facebook platform and with the effect it has had on his company. In just three months, the iLike Facebook application has close to 7 million users, almost twice as many as on the company's own Web site, leading to a doubling of the company's revenue, Partovi said.

Unlike other social-networking sites, which limit the revenue-generating capabilities of external applications, Facebook has a policy widely considered generous, letting development companies run ads and engage in other commercial activities.

This has contributed greatly to the attractiveness of the platform for developers. At press time, Facebook's directory showed over 3,500 applications built for the site by outside developers.

"The monetization is one of the most unique things they are doing," said Tim O'Shaughnessy, a co-founder and partner at Hungry Machine, which has developed about 15 Facebook applications. "That's what's causing the fervor over the application development. People are looking at the potential to enhance their business. It's not just a distribution play. It can put real dollars in your pocket."

Joseph Aigboboh, co-founder of J-Squared Media, another Facebook developer, agreed. "Facebook has created an opportunity to build literally any product and spread it virally to achieve unprecedented rates of growth and retention. This means that with a relatively cheap budget, companies can build lucrative products and services [and] drive revenue," he wrote in an e-mail.

It's no surprise then that some developers have been overeager in their attempts to boost adoption of their applications and generate revenue, while looking for ways to bend the rules.

Facebook responds

This week, Dave Morin, Facebook's senior platform manager, addressed the concerns about annoying and abusive applications in an official blog posting, and announced steps have already been taken, with more coming.

Facebook wants the popularity of applications determined by how useful and entertaining they are. Thus, it's shifting how it measures application popularity in its applications directory away from total users and toward user engagement, he wrote.

Vowing to protect members' experiences on the site, he said the latest release of the Facebook Markup Language -- version 1.1 -- changes how profile boxes display content, removing applications' ability to display profile content to visitors and hide it from profile owners.

The company is also limiting applications' ability to contact members to crack down on spamming of deceptive and misleading notifications.

Facebook's user experience has traditionally been considered significantly more elegant, controlled and organized than the one from key rival and social-networking leader MySpace.

Although MySpace remains more popular, Facebook has been gaining momentum for the past 12 months. Its user ranks have ballooned to 37 million active users today from 12 million in December. Over half of its active members return to the site daily.

Facebook widgets on the Slide

Slide, which creates widget applications for social-networking sites and is big on MySpace, jumped on the chance to set up shop on Facebook, which has quickly become one of its most important platforms.

Although Slide has created some of the most popular Facebook applications, its detractors have criticized it for engaging in some of the inappropriate tactics flagged by Morin.

But Slide's CFO Kevin Freedman said that Slide is as interested as anyone else in providing a good user experience on Facebook and elsewhere.

"We listen to our users' feedback first and foremost. Regarding some of those [critical] comments, we haven't necessarily seen the same response from our users and that's really what drives us," Freedman said.

Chris Kirkland, CEO of MrKirkland.com, a Web design and development firm, has created three applications for Facebook, but has been unimpressed with the developer program. "I very much consider Facebook to be 'learning on the job' with the development platform," Kirkland wrote in an e-mail.

The tools and resources Facebook provides to developers could be better, he wrote. "Overall we have been extremely disappointed. The documentation is reasonable, though sometimes inaccurate but by far our main complaint is the diabolically poor level of communication. We have a feeling that we are dealing with a bunch of over busy college kids," Kirkland wrote.

He blames this lack of communication for a situation that led Facebook to yank one of his company's applications from the site with, he says, nary an explanation and, in his view, without justification.

The application, designed to let members track visits to their profiles, received initial approval from Facebook, but then the company turned around and banned it because it lacked a feature Kirkland says they never told him would be required.

He's fuming that a similar application from a competitor continues on the site. "We were given no opportunity to alter the application, no warnings that they would do this, and my attempts at discussing the erroneous TOS reports with Facebook merely received generic replies," he wrote.

A lack of response?

Aigboboh, of J-Squared Media, also sees room for improvement in communicating with developers. "The main issue we see is that Facebook doesn't allow its developer community to interact with Facebook itself very well," he wrote, adding that he suspects Facebook is aware of this and working to correct it.

On a related matter, Hungry Machine's O'Shaughnessy, echoing others interviewed, said Facebook could also do a better job of giving developers advance notice of changes on the platform back end that require applications to be adjusted.

Ultimately, most developers interviewed said they hope Facebook will rein in the overeager developers and smooth the other wrinkles in the program.

"The platform is still very young. As it matures, it'll get more robust and problems we experience today will start to go away," O'Shaughnessy says. "For the stage at which the platform is, we're pretty happy with it."

"The people behind the Facebook platform are very smart. I'm confident they will take more steps to improve this," iLike's Partovi said. "It's like the Wild West now, but I don't think [the abuses] will last very long."

Facebook didn't respond to several requests seeking comment for this story.