Recovery isn't always enough. At least not for Google Inc.

Investors expect that first-quarter results due Thursday from the Internet-search company will show the online-ad market continues to rebound. Revenue, minus commissions to partners, is forecast to climb 21% from a year ago to $4.93 billion for the quarter, according to Thomson Reuters.

The gains come amid what are likely to be signs of improved search-advertising spending from two sectors hard hit by the recession, finance and autos. A recent report also showed that Google was the only major advertisingportal to increase its share of the ad market from 2009 to 2010, and the only one expected to do so in 2011.

That is all well and good. But what investors really want to know is what comes next, and what impact a slew of regulatory issues has on the business. Unease on both has dogged Google's stock this year; the shares are down 5%, while the Nasdaq Composite Index is up 10%.

Among the concerns: the Federal Trade Commission's review of Google's acquisition of mobile-advertising company AdMob, European antitrust complaints, and the company's clash with authorities in China over its decision to stop censoring its search engine in the country. There also are threats such as Apple Inc.'s foray into the mobile-ad business, as well as questions about weakness in Google's pricing power for search ads.

More important, Google needs to find its next profit pool beyond search ads. Marianne Wolk, senior Internet analyst with Susquehanna Financial Group, said she wants more details about momentum in nonsearch businesses like display and mobile advertising. Without growth beyond search, Google's valuation of about 21 times forward earnings becomes more challenging.

Costs, too, are something of an issue. After a year of layoffs and other cuts, Chief Executive Eric Schmidt has proclaimed in recent quarters that the company is ready to start spending again. Ramping up too quickly, by, say, rapidly expanding employee headcount, could crimp margins and give the impression that Google has abandoned its recession-induced restraint.

Until investors know Google's second act will be as good as the first, more may walk out on the show.

Jessica E. Vascellaro