It depends on two things. First of all you don’t want to kill everybody by having them hear your name every 10 minutes. But, you can use all these as nice intermezzo’s before you go on the mic for example or if you want to do a drastic genre change. The other thing is, if you play a wedding with most of the guest staying most of the night, then I’d do it when introducing myself as the night “really” get’s started and obviously shortly before the end (make sure you go out with a nice track that has everyone wanting more) and probably once or twice more during the evening.
If you are playing in a venue with crowd turnaround being frequent because of new folks entering other folks leaving I’d be ok with once or even twice an hour (provided you have different ones, if you only have one, then once an hour would be my max). After all you’d want everyone that was there that night to know who was on the tables, right? And with a minimum stay of about an hour, you’d cover just about everybody.
Make creative use of it, let it support, not disrupt the flow and try to fit it in naturally not as some kind of uber-statement.
My 2$50 again.
Greetinx.
<edit> obviously if you have video capabilities in your DJ software and a beamer or 42-50″ plasma/led to play with, that gives you infinite more ways of promoting yourself without it interrupting anything in the music and/or support the audio message when you play it.
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