Yes. Many developers choose to host their own add-ons. Choosing to host your add-on on <a href="%(amo_url)s">Mozilla's add-on site</a>, though, allows for much greater exposure to your add-on due to the large volume of visitors to the site.
Jo. Wjele wuwijarjow góspodujo swóje dodanki same. Jolic pak góspodujośo swój dodank na <a href="%(amo_url)s">sedle dodankow Mozilla</a>, změjośo wětšu zjawnosć za swój dodank pśez wětšu licbu woglědowarjow na toś tom websedle.