Once one of the fastest growing companies in history, Groupon (NASDAQ:GRPN) has struggled since its public debut in 2011. Shares are down nearly 70% since its IPO, and more than 44% just this year. The business that it was built on -- daily deals -- seems to have been a fad that has run its course.

Groupon has persevered, largely because of intelligent pivots, but has been a clear disappointment for shareholders. Still, after shedding so much market cap, Groupon could be a bargain at these levels. This of course begs the question, should investors put their  hard-earned money to work?

Difficult to value
It's hard to put a reasonable value on Groupon's business -- its history as a publicly traded company provides perfect evidence. When it first began trading, Groupon was valued near $13 billion, but today, its market cap is around one-third of that.

Groupon has no true price-to-earnings ratio, as it hasn't been consistently profitable in recent quarters. Even based on future estimates of profitability, Groupon's valuation is still relatively high, with a forward price-to-earnings ratio around 32.

Groupon's management claims it has no true competition, which appears to be an accurate assessment. Once, Groupon had several competitors in the daily deals space, notably LivingSocial, but most have fallen by the wayside. Originally built on daily email blasts, the company has slowly shifted to featured deals that run on its website for an extended period of time.

Groupon has also embraced the sale of physical goods, which sort of puts it into competition with firms like Amazon and eBay, but it would be disingenuous to compare Groupon to those firms. Physical goods, despite bringing in a great deal of revenue, don't add much to Groupon's profit. Moreover, the sorts of goods it sells (close-out items, refurbished electronics, and other goods that are randomly available and only for a limited time) don't compare to the department store experience offered by traditional online retailers.

Building a platform
In the absence of daily emailed coupons, Groupon has shifted its long-term business goals to the construction of a local commerce platform. In the most optimistic scenario, Groupon would come to be the central hub local merchants use to interact with customers.

There is some evidence that this strategy is working -- Groupon's app now brings in most of its revenue, and has been downloaded more than 92 million times. The company is making improvements in the form of initiatives like Groupon Pages (merchant landing sites), and the move from daily deals to featured deals creates a marketplace of deals consumers can browse at any time.

A speculative investment
To put it simply, there's not much to like. Its recent performance has been atrocious, and because it isn't profitable, it certainly isn't a value play. Revenue is growing (up 23% on an annual basis last quarter) but the profits are not following (gross profit up just 1.3%).

Concerns about Groupon's accounting have plagued the company since its debut. In particular, the company has been criticized for in its inability to provide consistent guidance -- that trend continued last quarter, when Groupon lowered its full-year adjusted EBITDA outlook by 10%.

Establishing a true online local commerce network would be novel, but such a business model obviously remains unproven. It's certainly possible that Groupon could reward its shareholders, but until it can achieve profitability, all but the most aggressive of investors may wish to stay away.