If you can keep it well stocked, and advertised in "/ch tr", Yes.

 

A spawnshop is better than a shop in a town, but spawnshops can generate their own traffic, if they're close to the warps.

 

It's a tricky and risky business. I myself have never owned a spawnshop, but if you play your cards right, you can make a profit.

 

Haven't owned one myself, but several of my friends have made huge profit...and many others never made a profit. It has to be kept up-to-date on prices and stocked, as well as watching a lot of the current going prices in trade every day. Really is more of a business compared to shops in towns because you have so much competition surrounding you.

 

How much profit do they produce you think?

 

Personally I have ran many levels in the old and new markets. In the old ones I only ever owned the bottom floors but at various locations and usually they made around 5-10k/day with advertisements.

Now in this market I have run 4th, 5th, 6th and 8th row shops. Really with the new warps for all shops they make a ton of money with advertising. Almost double what the previous markets made. And advertising/pricing is really the key. If you take time to work on your shop, it will work for you. If you have better prices than other shops, you will get loyal customers. These people know your shop is good and keep coming back. Also they may tell people about your shop.

Tl;dr
Yes, they are worth it if you put in the effort.

 

I have a Station 5th in row. Yellow Market. You must understand it takes patience. Sometimes, in the first month, you won't make a profit yet keep advertising and work hard. For the last 2 weeks of this new shop, I have made like 15k off it. Just recently it's been wracking up 10k/day.

Tl;dr

Patiece and faith is key.