HONOUR OF AN ALIYAH
In all Jewish communities, it is considered a great merit and honour to be called to recite the blessings at the Torah. It is referred to as an "Aliyah," which means "ascent," referring not just to the climb to the platform upon which the Torah is read, but also to the spiritual elevation which comes along with this opportunity.
Furthermore, when one has an Aliyah to the Torah, all parts of one's soul, including those which are in the spiritual realms beyond this world, experience an elevation at that moment. For this reason, people vie for this privilege.
It is for this reason that it is customary to give a donation (as Tzedakah - Charity) when bestowed such an honour, to acknowledge how one values this special honour and to concretely express the effect of a Mitzvah through the funnel of Tzedakah.
Your contribution helps the Shule to continue to grow and thrive.
Many have the custom to contribute in multiples of 18, the numerical value of the Hebrew word 'Chai,' meaning 'life.'