CBS Corp. is acquiring a big online reach with its acquisition of CNet Networks Inc. but also a company that’s faced heavy criticism from investors. Those concerns as well as the hefty $1.8 billion price tag helped send CBS’s shares down after the deal was announced Thursday.

CNet was an early player in the dot-com boom and survived the subsequent crash with a steady focus on technology news, reviews and entertainment. But its stock, which once traded as high as $79 during the bubble, has slumped over the last two years, leading to an investor rebellion that was gathering steam just as the CBS deal was announced.