If a guy responds to online chats, but doesn't ever initiate, does that mean he's interested?

Hi, I met a guy online whove I been chatting with, pretty infrequently lately because hes not online a lot but whenever he's online, we have pretty decent convos. However, I have always been the one to initiate. But once I do, he responds back right away and chats with me as though Im the only one hes talking to. However, he's never asked me out or hinted that he wants to meet/chat on the phone and its been quite awhile...though if he wasn't interested at all, wouldn't he just not reply to my IMs? I want to think he's interested, but I really want to know the truth. thanks!