Facebook’s (FB) life as a public company has been nothingshort of rocky, but Oracle’s (ORCL) CEO Larry Ellison thinks it might be even more important than Google (GOOG). Pivotal Research analyst Brian Wieser agrees with Ellison that Facebook’s story is likely to get better over time, and upgraded the company to “buy” with a $30 price target.

Wieser believes Facebook’s fundamental story is likely to get better, according to a note released on Thursday. By late 2012 and 2013, optimism is likely to increase as investors become more comfortable with the issues the company is facing. “Facebook will by then have cycled through difficult comps and investors can better focus on the fundamental growth story,” Wieser wrote.

Sentiment surrounding Facebook has been extremely negative, with attention focusing on the company’s slowing revenue growth. TheStreet noted that investors could have something to worry about as the social networking giant’s IPO increased in size and scope.

Facebook has repeatedly listed mobile growth as one of its biggest challenges, if not the major risk to the company’s revenues. The Palo Alto, Calif.-based firm recently tried to combat this by announcing its intention to buy Instagram.

“To ensure long-term growth, Facebook needs to generate more revenue from mobile users who represent the largest percentage of growth,” Jeff Sica, chief investment officer of Sica Wealth Management said in a recent email to TheStreet. “In order to achieve this revenue, they must increase the time mobile users spend online to justify higher advertising fees. They must also shrink ad size for mobile users to increase the number of users.”

Despite the upgrade, investors need to be wary of high capital expenditures (likely to be around $2 billion), acquisitions such as the Instagram purchase which do not have a return profile, and rising operating expenses, Wieser said in his note.

There are also concerns about competition, including Google, as Facebook continues to build relationships with small and medium-sized businesses. “Google and other companies will persistently nip at the heels of Facebook, looking for points of entry to capture a share of Facebook’s market opportunity,” Wieser added.

The Street