From Snap’s IPO to Facebook’s ad breaks to Instagram’s Sto­ries, here are 2017’s biggest sto­ries in social so far.

The social mar­ket­ing land­scape shifts so quick­ly that a half-year review isn’t so much ridicu­lous as almost req­ui­site, if only to keep track of what has changed already in 2017.

When 2016 end­ed, Snapchat was a social dar­ling, Face­book videos could be watched unin­ter­rupt­ed, and Instagram’s Sto­ries prod­uct was small­er than Snapchat’s orig­i­nal. Then 2017 hap­pened. More specif­i­cal­ly, these things hap­pened:

Snap went public

Secre­cy had always been part of Snapchat’s allure, but when the app’s par­ent com­pa­ny Snap filed to go pub­lic in Feb­ru­ary, it lost some of that mys­tique, in part because it appeared to be los­ing its war with Insta­gram. Soon after Insta­gram cloned Snapchat’s Sto­ries fea­ture, Snapchat’s audi­ence growth slowed. By April 2017, more peo­ple were check­ing out Insta­gram Sto­ries dai­ly than open­ing Snapchat. Those stats alone would have made for a rough start to 2017. But in May, Snap said that its Q1 2017 rev­enue slid from the Q4 2016 mark because of sea­son­al­i­ty, a trend that’s nor­mal for a sea­soned ad busi­ness but unusu­al for an upstart.

Instagram’s Stories audience overtook Snapchat’s

After clos­ing 2016 by mak­ing run at Snapchat’s user base, Insta­gram opened 2017 by mak­ing a run at its rival’s adver­tis­er base when it rolled out Snapchat-style ver­ti­cal video ads between people’s Sto­ries. Then in April — two months after Snapchat dis­closed its dai­ly user count for the first time — Insta­gram revealed that more peo­ple were using Insta­gram Sto­ries dai­ly than Snapchat. Then in June, a month after Snapchat said that its dai­ly audi­ence growth had rebound­ed by 5 per­cent from Q4 2016 to Q1 2017, Insta­gram announced that Sto­ries’ dai­ly audi­ence had grown by 25 per­cent from April to June.

Facebook rolled out mid-roll ads

Views are nice, but rev­enue is nicer. After build­ing itself up as a legit­i­mate alter­na­tive to YouTube for cre­ators and pub­lish­ers to attract audi­ences for their videos, Face­book final­ly start­ed test­ing a way for com­pa­nies to make mon­ey from the videos they post on the social net­work. Now it’s a ques­tion of whether adver­tis­ers shak­en by YouTube’s “adpoca­lypse” are com­fort­able with Facebook’s lim­it­ed con­trols over which videos fea­ture their mid-roll ads.

Twitter gained users, lost money

In the movie “Nation­al Lampoon’s Vegas Vaca­tion,” Chevy Chase tries to plug a leak in the Hoover Dam, only to have anoth­er one open. Twit­ter is Chevy Chase. The com­pa­ny has final­ly re-accel­er­at­ed its audi­ence growth, but now its total rev­enue and adver­tis­ing rev­enue are in decline. And while Twit­ter has added more mon­ey-mak­ing ad prod­ucts, like ads in Periscope, it has also lost one of its most mar­quee sales oppor­tu­ni­ties after the NFL opt­ed not to renew its reg­u­lar sea­son live-stream­ing deal with the com­pa­ny.

LinkedIn turned on retargeting

Busi­ness-wise, LinkedIn had stayed pret­ty qui­et since being bought by Microsoft in 2016. Then the the busi­ness-cen­tric social net­work final­ly opened itself up to retar­get­ed adver­tis­ing through a new pro­gram called Matched Audi­ences. While LinkedIn isn’t doing any­thing that hasn’t already been done by Face­book, Google, Twit­ter — real­ly, by every­one — it can bet­ter cater to B2B mar­keters.

Pinterest put a new Lens on visual search

Pin­ter­est wants to do for visu­al search what Google has done for text-based search. But for a search engine to be tru­ly visu­al, not only should the results be visu­al, but so should the queries. And so in Feb­ru­ary, Pin­ter­est rolled out Lens, a fea­ture in its app that con­vert a phone’s cam­era into a search bar. A few months lat­er, Pin­ter­est said that it would use the same com­put­er vision tech­nol­o­gy pow­er­ing Lens to tar­get ads on its plat­form.

Facebook’s Messenger raised chatbots’ profiles

2016 was sup­posed to be a big year for chat­bots. Luck­i­ly for them, it was not. But 2017 may be after Facebook’s Mes­sen­ger added a Dis­cov­er tab to make peo­ple more aware of the chat­bots and busi­ness­es on its plat­form.