Investors think Facebook’s revenue growth may finally slowwwwww down.

Facebook has been warning investors for the past year that its revenue growth would slow “meaningfully” in 2017 because it has finally run out places to put ads in News Feed.

So far, that slowdown hasn’t really happened. At least not meaningfully, though year-over-year revenue growth has declined each of the past four quarters.

Facebook year-over-year revenue growth

On the company’s Q1 earnings call in May, CFO Dave Wehner said the revenue slowdown would be “particularly pronounced as we get into the second half of 2017.” Q2 is not technically the second half of 2017, but it’s possible that Facebook may start to show some signs that revenue growth is indeed slowing meaningfully when it reports Q2 earnings Wednesday afternoon.

Investors seem to think it will. Analysts are looking for profits of $1.12 on revenue of $9.2 billion for the quarter. That would be almost 43 percent revenue growth over the same quarter a year ago; certainly not bad, but also not where Facebook has been the past two years. It would mark the company’s smallest year-over-year revenue growth jump since mid-2015.

Facebook is trying to find an advertising complement to News Feed to help revenue growth continue. It’s testing ads in a bunch of new places, like Messenger and Instagram, and is gearing up to start making money from its standalone messaging app, WhatsApp, sometime soon.

Many believe that Instagram may be the company’s next big-revenue business. Facebook, though, has never broken out Instagram’s revenue numbers before.

The good news in all this? Facebook is still an advertising powerhouse, especially on mobile. A big reason that people are expecting a revenue slowdown is because Facebook’s revenue numbers are so large to begin with.

Facebook is expected to bring in $32 billion in worldwide mobile ad revenue in 2017, according to estimates from eMarketer, second only to Google. Facebook’s user growth has also stayed strong; the social network added 76 million new users last quarter alone. It now has more than two billion total users, a milestone the company announced in June.

Facebook’s challenge now is finding a way to actually make money from many of those users who are joining from parts of the world with weak internet connectivity and advertising markets.

Facebook made over $17 per user in the U.S. and Canada last quarter, but users from the company’s “rest of world” category, which includes users in South America and Africa, brought in less than 10 percent of that number. Facebook’s business is incredibly reliant on the world’s largest ad markets, not necessarily where its new users are coming from.

Facebook reports Q2 earnings after markets close on Wednesday.