It is an art form in itself, and much of it depends on an understanding of psychology. True some can be achieved just by going through the motions without that understanding, but applying psychology with understanding will get you much further.
Visitors to your page need to be conditioned from their first encounter. It starts with how they find your artist page and their expectation when they get there. On many occasions you will not have control of exactly how fans find you, but you should take advantage of how your music is found where you can. The language on your page,
Overall, the answer to your question is a huge topic. Some practical steps to increase downloads would perhaps be a good start lol
I would ask if your fans are used to getting free downloads or paid?
As mentioned many factors need to be considered. The language and images used on your artist pages, focused on encouraging downloads, using "action statements" which is a fancy way of giving your visitors instructions in a way that they are more likely to be followed (a standard method of marketing and promotion).
On the internet, or for that matter on mobile phones, one of the key assets in your internet marketing campaign is your mailing list. How you run your mailing list is key to success of the whole venture, though I would now also add social media, as both are ways for you to communicate directly with your fans. The perception of your products, your music, is set via your website, social media, media and the most direct of methods, your mailing list. By being direct you can completely control what you tell your fans, and when you tell your fans. This is exactly how and where you start to condition visitors and fans to be more likely to buy your music or other product. The product has to be framed in a way that makes it highly desirable, with a degree of urgency to their actions.
When you release a product of any kind, you do not want to start by selling to a "cold" audience. You want to sell in what is termed a "warm" market, ie the audience are interested in what you say, what you are talking about. It is up to you to heat the market up and GIVE them a strong appetite for your music. In any marketing and promotion this can be enhanced by using PR effectively to attract people already interested in your music, who have already gone to the effort of visiting your website and encouraged to join your mailing list. You can see that each step back in the chain we go we have more to consider, more things to do, in order to effectively convert someone from a listener to a paid downloader.
The basic flow is simple:
In the first place, talk to people who are more likely to be converted into your fans
Get them on your mailing list <- KEY
Talk directly to your fans and at all stages encourage their appetite for your music, for you.
Coordinate your song releases
Build the appetite and expectation weeks before song release, using PR, mail outs, press releases, reviews etc.
Highlight previous releases and encourage fans building upon your back catalog, if you have one
Release your song to key press agencies to get those reviews
Mark the release, with perhaps a launch party
Follow up the release with more publicity and PR, interviews, special offers and, of course, gigs.
On that point, it is likely that Songstuff will be bringing out a range of products to help with all this, giving both background psychology of music marketing and detailed individual steps you can follow, covering the entire process.
One other thing I will mention, is the lessons of preparation, and that of patience. Prepare, prepare, prepare. Get all your graphics, mailing list messages, web text, press releases, song registrations and more put in place BEFORE you even start the warm up. Why? Timing is everything. The lesson of patience is exactly that, your capacity to wait until everything is prepared before you start your public campaign.
The whole point in all this is:
To attract people likely to buy your music
To give them a strong appetite to do so by every means you can
To motivate them to buy
To actually increase your sales
I don't have time to expand further just now, but hopefully you can get something useful from this rambling message.