1. Contextual advertising (in Yandex and Google) - paid (the price is different for everyone, it all depends on the price of clicks and the number of keywords);
This is the best and most direct tool for online sales. From contextual advertising (Yandex Direct and Google AdWords), only target users reach your site because you make your own selection of keywords for which your ad is displayed.
2. SEO promotion - paid / free (the price depends on the simultaneity);
Search engine optimization is also one of the most effective ways to promote your business on the Internet. Also, for your business website, I would definitely recommend using SEO. Being in the TOP 3 search results for targeted queries for your business is very profitable! So the result of good search engine optimization is to enter one of the first three positions.
3. Direct sales - free / paid (costs depend on the number of direct sales specialists);
4. Free bulletin boards are free;
5. Active audiences and groups - mostly paid (the price depends on the selected audiences and groups);
6. Hidden advertising - paid / free (the price depends on the strategy and the selected sites).