Digital scrapbooking company Pinterest (PINS) beat Wall Street’s sales expectations in its first quarterly report since going public, but a weaker-than-expected full-year outlook sent shares sharply lower during extended trading.The company reported first-quarter sales of $201.9 million, topping estimates calling for $200.8 million. Excluding certain items, Pinterest’s loss came out to 32 cents per share, wider than the about 10-cent loss Wall Street had been expecting.In the year-ago quarter, Pinterest posted revenue of $131.4 million and a 38-cent adjusted net loss per share. For the full year, Pinterest said it expects to see revenue between $1.06 billion to $1.08 billion, lower than the $1.09 billion expected. Shares fell 17.17% to $25.56 each as of 4:37 p.m. ET, falling below $26 per share.