Well, I don’t know about a billion dollars—I’m no venture capitalist. But over the past couple of weeks I’ve realized that Instagram has become my #1 go-to social app: if I’m waiting in line at the bank or hung over in bed, I’ll open Instagram before checking Twitter or Facebook or even Tumblr. Why is Instagram so great right now? Here are five things it’s got going for it.

1. It’s a visual Twitter. “Limits equal freedom” sounds very Big Brother, but it’s a lesson Facebook learned from the sparkly train wreck of MySpace, and that Twitter learned from Facebook, and that Instagram has now learned from Twitter. Instagram doesn’t have any links or events or apps or even GIFs—it’s just a steady stream of photos. There’s something soothing about that; you can watch it like a movie.

2. Filters. There’s been much discussion about whether Instagram filters are for twee dilettantes (versus Serious Photographers), but take away the names and the frames, and Instagram filters are really just an accessible version of the tools Serious Photographers have always had access to: changing brightness, contrast, and saturation. A filter can’t make a bad photo good—no more than Photoshop can fix a screwed-up DSLR shot—but it can enhance and clarify, making the photo more attractive and effective. Having that tool onboard is a no-brainer for a good photo sharing app.

3. Integration. I use Instagram for almost all my photo posting now, because it’s so elegantly integrated with other social media: when you post a photo to Instagram, you can easily select which other networks you want to share it with. Best of all, for whatever reason it’s much more reliable for uploading than most Twitter photo-sharing services, and way more reliable than the Tumblr app. It’s just the fastest and least frustrating way to share your photos online.

4. It’s at the sexy sweet spot of network adoption. You know that point in a social network’s life when it seems like it’s used by all the people you want to see your shit, and none of the people you don’t? Facebook toppled off this peak years ago, Twitter’s on its way downhill, and right now Tumblr and Instagram are sharing space at the summit. Chelsea Fagan recently wrote on her Tumblr, “I just took the time to write a bottom-of-the-barrel-scrapingly witty status on Facebook and I just kind of sighed and thought, ‘What the hell am I doing here? I don’t want approval from that pregnant chick I went to high school with and my bullshit new-agey aunt.'” That pregnant chick and the new-agey aunt have their Facebook (and Pinterest), and the rest of us have Tumblr and Instagram. For now.

5. It’s mobile-only. Well, not purely. If your Instagram account is open, your photos exist on individual Web pages that are linked to when you share your photos. But those pages aren’t linked to each other, so you can’t navigate Instagram on a browser: you have to use the mobile app. (Try the Instagallery app for your iPad; it feels like seeing your favorite classic movie on the big screen.) That gives Instagram a feeling of intimacy and privacy that makes it feel weirder to follow a stranger on Instagram than it is to follow him/her on Twitter or even to friend him/her on Facebook. Instagram still feels like a little mobile clubhouse. Will Facebook be able to preserve that feeling? Probably not, so enjoy it while it lasts.

– Jay Gabler