You have gotten many good tips, but I will throw in my 2 cents here.

I owned an aquarium and pet store along with an aquarium maintenance and design business from 1978 to 2002.

For us the money maker was the maintenance and design business and everything else was designed to support this endeavor. This is not to say that the store did not make money only to say we did not worry too much about what others were doing and concentrated on what we did best. We had several major accounts and many potential new accounts came to our store just to see displays or to look at fish that they might like, so we sold fish accordingly. We did sell many unusual fish, but also bred and butter common ones as well.

We also tried to bring new customers into the hobby and we often helped new hobbyists that bought their tanks elsewhere.

People came to know that we sold what we used in our service business and worked best and not what was simply the popular industry fad at the time. We sold fish foods and products that worked that could be had nowhere else as well (such as unique UV Sterilizers, aquarium mineral blocks, and more).

As to profit margins, as bikeguy said those are low margins except for aquariums.

As stated earlier many of the products we sold were unique so we did not have to compete as much on price and in the case of products that we sold that were also to be found at the Petcos and similar we purchased as smart as possible. For example the largest Wholesaler in of mainline aquarium products is Central Pet, so to compete with the buying power of the big guys we jumped through a “few hoops” which were pre ordering the items we needed and then picking up at the wholesaler, paying upon pick up, purchasing over $600 PLUS using their vender days (Tuesday, Thursday) to get an additional discount and planning to stock up as per the chosen vendor. The result was for example, Marineland products could be had for a 29% discount by buying smart and often we would then mark up and additional 10% and still make a could margin and be no higher than PetsMart, etc.

Of coarse we also sold many items as earlier stated that were sold through distributors that sold only high end products through specialty stores and not the PetCos, etc.

I also developed direct contacts through the years with many in the industry that allowed me to buy more direct. My relationship with many Chinese business contacts buy respecting them and treating them as friends (I have been invited to weddings and family gatherings as well) and not just persons to use for a means to an end also furthered me here and today is how I am able to purchase many items directly.

Summing it up:

*find a niche

*Be unique

*know your product

*Continue to push your service

*Make sure that what you sell is a good product

*Same for your service; be unique with your knowledge, do not follow the anecdotal herd.

*Improve your margins

*Know your competitors, but do no necessarily copy them, just know their strengths and weaknesses.

* And of coarse (from my college business courses), location, location, location

I do not normally answer at Yahoo Answers anymore, but came here as a friend (Jon V) asked.

My schedule does not allow time here, but I along with bikeguy and Jon V can be found at: http://groups.msn.com/EverythingAquatic