COMPILED REGEX.cs

var watch = new Stopwatch();

var htmlString = "<div class='isc-content-block' data-contentmanagerid='60dd19b0-e3ba-4629-935c-a2dd00e052b8' data-contentmanagername='Product: B456009805'>456009806</div>";
var regex = new Regex(">(.*)</.*>", RegexOptions.None); // NORMAL REGEX

// REGEX START
watch.Start();

// WARM UP JITTER
for(int i = 0; i < 10000000; i++)
{
	regex.Match(htmlString);
	// watch.Restart();
}

// END RESULTS
regex.Match(htmlString);
watch.ElapsedTicks.Dump("normal regex ticks");
watch.Reset();

// SUBSTRING START
watch.Start();

// WARM UP JITTER
for(int i = 0; i < 10000000; i++)
{
	htmlString.Substring(htmlString.IndexOf(">") + 1).Replace("</div>", string.Empty);
	// watch.Restart();
}

// END RESULTS
htmlString.Substring(htmlString.IndexOf(">") + 1).Replace("</div>", string.Empty);
watch.ElapsedTicks.Dump("substring ticks");
watch.Reset();


// REGEX COMPILED START
regex = new Regex(">(.*)</.*>", RegexOptions.Compiled); // COMPILE
watch.Start();

// WARM UP JITTER
for(int i = 0; i < 10000000; i++)
{
	regex.Match(htmlString);
	// watch.Restart();
}

regex.Match(htmlString);
watch.ElapsedTicks.Dump("compiled regex ticks");
watch.Reset();