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Forum Moderators: buckworks
As Brett pointed out, 10% click-to-buy is a near unobtainable ideal, and your 6.13% sounds pretty good to me. Similarly, a 7% visitor-to-click rate is pretty good. I would expect a banner ad to do less than 1% these days (unless you have an AMAZINGLY targetted ad space), so you must be doing a lot right already
Can you track what keyword/phrase is associated with a given visitor, and then track that through to a buy/no buy decision? If so, then identify the words/phrases that have the highest %age of purchasers, and try to hit those keywords harder.
Alternatively, maybe try creating some alternative versions of your banner, and try them out for a week or so each. See which ones do well, and try to work out why. Play with different wording, different layout, different colours. You never know, you may find the magical mix that gets it just right (but bear in mind, you may be pretty close to that already)