Text message marketing is one of the best and most cost-effective ways to reach your customers. Once you conduct a campaign, it is important to periodically review metrics to ensure that it's working the way it is intended. Here are some signs that you might need to rethink your SMS marketing strategy:

High opt-out or low opt-in rates
The best way to gage your audience's interest in your SMS marketing campaign is through opt-in and opt-out rates. Obviously, any campaign will have both of these in some capacity but, ideally, you'd like to have low opt-out rates with high opt-in rates.

For opt-out rates, if you see unsubscribes suddenly jump or gradually increase above the 3.5 percent mark, then that's a sure sign that you need to rethink your strategy.

Opt-ins are a bit different. When you first introduce a campaign, you will naturally see a big spike in opt-ins. This will gradually plateau. While you are unlikely to see them spike like they did when you first started the campaign, you want to make sure that you are constantly growing your base. Once you hit the plateau, try different things to help that rate climb.

A lot of bad numbers
Like opt-ins and opt-outs, bad phone numbers are a given in text message marketing campaigns.  But if your bounce rate gets too high then you might be doing something that isn't as effective as it first appears. One way to combat this is to make sure your message frequency is high enough to maintain an accurate subscriber list.

Low redemption and conversion rates
All the subscribers in the world aren't going to help you if they're not taking advantage of the offers you're sending out. While some subscribers may just use the service for informational purposes, it's important that redemption and conversion rates remain high, as they're what drives sales. If these numbers are too low, or you see them starting to drop, you may need to make some modifications to your offers.

No change in sales
SMS marketing campaigns should lead to increased sales. If sales remain the same, then you need to revise your strategy. It's important in these situations to make sure that customer awareness of your SMS service is high, as it may a simple to fix as boosting your opt-ins.

No impact on other channels
Text message marketing is typically able to prop up other sales and marketing channels. It offers near perfect open rates, read within minutes of their receipt, so its impact should be able to bolster other channels.

In general, you should always be reviewing and changing your SMS marketing campaign as needed. This is the best way to keep your customers engaged and satisfied. A powerful SMS gateway can help you leverage the buying power of your SMS subscribers.