It is useful if you have a piece of wood wider than your jointer, narrower than your planer, shorter than your sled, thick enough for your clamps to grab, not heavy enough to bend your sled, and you only want to face joint it. That leaves out 99.5% of the wood you'll ever want to joint, as well as edge jointing. Edge jointing can be done on a table saw or a router table, but I don't think you have either of those things either. And in both cases it only works so-so.
@Voltron and I have both recently purchased combo jointer planers from Hammer. Al is still waiting on his, and mine arrived after a 3 month wait only to sit in the garage due to movers failing to be able to get it to the basement. But I'm with @swt61that a small benchtop jointer makes sense until you think you are going to use it a lot. This one is fine for most things.
Alternatively, you can joint things larger than any power jointer with one of these for far less money.