Well...
It's never ending.
Go look at 'sales' books for sale...thousands. if it was a one word or even paragraph answer it would be simple..but alas, it is not.
I get hit up weekly, if not daily "Advertise with us - double your business!!"...well, if it truly worked they'd probably not have to work too hard to sell their advertising product, huh?
What to charge...MANY variables on that, few if any concrete like if you sold pizza or gasoline or used cars. And what is the industry 'norm'? Most all industries have that info - DJ's..well, not really.
I can tell you if you spend 2% of sales or 40% of sales in marketing a restaurant you're likely to fail (too few customers, to little profit left over). What's right for a DJ business?
Does it vary by what you're marketing (school, party, wedding, bar?), if you've been around 5 months or 5 years? If you're aiming at $3000 weddings or $500 weddings?
What about online? Much can be done for 'free' (cash wise) but is very costly in time. So..how much TIME should one spend on marketing? Websites, social media (and which one/s?)
What's a good closing rate? And how do you measure it? Leads...leads that replied..meeting..phone calls..emails...texts? From which source? Does time of year, or price point, or type of gig make a difference? Is most your leads cold, warm, repeat or referral? More importantly what does a lead cost you (by type maybe..by souce...) and what does a booked gig cost you? (in time, per gig, annually maybe...)
What makes the 'phone' ring? I'd say this year (as it changes) 80+ or more of my gigs, cold or referral or repeat, are email/fb/text...NOT on the phone or face to face.
So if you never get to 'talk ' to your prospects...how do you stand out, get your personality across? (is this a repeat or a new question?)
Same thing work for you today as 5 years ago? Will you make changes over the next 5 years? Of course...so it's ALWAYS changing.
And most folks that choose to be a DJ don't choose to be a marketing manager, business manager, cost accountant, etc. So yes, the questions keep coming...over and over again.