Compete.com has come out with their April traffic statistics, and it appears that Facebook has experienced its biggest month yet. With over 135 million unique visitors in the U.S., Facebook grew over 2.5 percent last month domestically and overall visits increased a whopping 15.7 percent, signaling that overall usage among users is increasing as well. While May’s statistics will be the ones to refute whether or not Facebook traffic stalled, April appears to have been another big month.

Twitter, the second most buzzed about social platform right now, doesn’t appear to be as large of a threat as it once was. However as many have noted before, unique visitor traffic to Twitter.com is not the best sign of how successful the company is performing. Instead, the absolute volume of tweets coming through the Twitter Platform is what’s most important.

Facebook is nearing 500 million active users, and while the total number of visitors to the site has easily surpassed that threshold, it’s difficult to track what percentage have registered. While all signs point to a June announcement from Facebook for the 500 million user threshold, we’ll have to wait on the company to make any official announcements.

For now, all the metrics we have access to suggest that Facebook is experiencing continued growth and Compete.com supports a similar conclusion.