Facebook (Nasdaq: FB) really needs to get on that "monetizing mobile" thing.

Latest data from Facebook has mobile users in the U.S. and U.K. popping 18 percent and 22 percent, respectively, last month. Facebook was providing the information as it looked to draw in more advertisers aiming to reach customers during the summer months.

When people are that engaged, checking their Facebook 14 times a day, if advertisers can deliver the right message to the right audience you can really see some business impact, commented regional director for Britain and Southern Europe, James Quarles.

Mobile revenues have been improving, with the metric accounting for around 30 percent of Facebook's total draw in first-quarter 2013. Shares of Facebook are up 0.4 percent Thursday.