Some will jump at a sale. But you can not build a loyal customer base with the latter approach. The soft sell in the middle of an article in which you are providing needed information will take you much further in the long run. If your visitor clicks on your link, it will be her choice. Thus at the other end of the link, you will know she arrived by choice.
Enthusiastic support is called for.
But so is lightness. And grace and style help as well. Something very simple may work best. Being the gardening fanatic that I am, I think I've tried every gardening tool made. Those I haven't tossed, lie rusting in the garage.