that's happening now - there's been lots of complaints on the U.S. FB page lately - my spidey senses started tingling way back when they made that change to Paypal - and the times the site goes down I am sure are deliberate, and done on a rotating basis
I've seen speculation that SBs is headed towards more of a shop and earn type of site, where you have to spend money to get SBs, and that the MyGiftCardsPlus is part of that
I will only do the videos/games/mobile apps on SBs since other sites don't offer that, but as for surveys & tasks, I would never do them here - other sites pay way more, AND in U.S. currency, which makes the difference even greater