Yes a Landing page is time consuming and cost, however a landing page will have a much higher conversion rate then a direct link, basically the time and cost is made up over time with a LP vs DL
Most all the offers i seen i know i would just leave if i was directed to there page as they are just not very creditable. Look at a most dating site, bunch of images of men and women and a register box in the middle, you Dl some one to that they are more likely to just close the page, now directing them to your lander when they do click your link it is because you already sold them on it and they are interested.
I personally do not care what offer i run i use a LP, why rely on there page that you have no control of when you can rely on your own that you can fine tune when ever you want to better increase conversions.